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1
Yang, Qi. "Résistance au feu de géopolymère alcalin et de de géopolymère acide." Electronic Thesis or Diss., Centrale Lille Institut, 2024. http://www.theses.fr/2024CLIL0014.
Full textAbstract:
Cette étude concerne les propriétés de résistance au feu des géopolymères préparés paractivation alcaline ou acide. La première partie passe en revue l’état de l’art sur ledéveloppement des matériaux géopolymères, leur processus de synthèse, les méthodesd'activation, les méthodes d'application et l'influence de leurs composants sur leurspropriétés. Un accent particulier est mis sur leur propriétés de résistance au feu. Les travauxconcernent les facteurs influençant la résistance au feu des géopolymères activés par desalcalins, notamment le rapport Al/Si, et la nature de cations utilisés. Les résultats montrentque plus le rapport Al/Si est faible, plus le géopolymère se ramollit à haute température (≥100°C) et se dilate en raison de la pression interne crée par la vaporisation de l'eau. Comparésaux géopolymères à base de sodium, les géopolymères à base de potassium ont un degré depolymérisation plus faible pour un même temps de polymérisation. Même avec un faiblerapport Si/Al, des silicates à faible polymérisation peuvent se former et provoquer l'expansiondu géopolymère. En revanche, les géopolymères à base de sodium subissent une réaction depolymérisation plus complète, mais perdent leur capacité de ramollissement à hautetempérature (≥ 100°C) et sont sujets à la fissuration.Dans des conditions d'activation acide, les géopolymères présentent également une bonnerésistance au feu grâce à leurs propriétés d’intumescence lorsqu’ils sont soumis à une sourceexterne de chaleur, similaires aux géopolymères activés par des alcalins. Le principal facteurinfluençant cette propriété est le rapport P/Al. Lorsque le rapport P/Al est élevé (≥ 0.74), duphosphore peu condensé est générée lors de la polymérisation, qui se déshydrate et secondense lors du chauffage, provoquant le ramollissement et l'expansion du matériau. Enraison de cette caractéristique d'intumescence, les géopolymères à faible rapport Al/Si(géopolymère alcalin) ou à haut rapport P/Al (géopolymère acide) sont des matériauxrésistants au feu prometteurs<br>This work deals with the fire resistance properties of geopolymers alkali- or acid-activated.The first part deals with the state of the art of the development of geopolymer materials,including their synthesis process, activation methods, application scenarios, and the influenceof their components on properties. A particular focus is on their potential benefit as fire-resistant materials. The thesis reveals the superior fire resistance of alkaline geopolymers andinvestigate the factors affecting the fire resistance, including the Al/Si ratio, and type ofcations. The results evidence that the lower the Al/Si ratio, the more the geopolymer softensat high temperatures (≥ 100°C) and expands due to the driving force of water vaporization.Compared to sodium-based geopolymers, potassium-based geopolymers have a lower levelof polymerization for the same curing time. Even with a high Al/Si ratio, low-polymerizationsilicates can form and cause the geopolymer to expand at high temperatures. In contrast,sodium-based geopolymers undergo higher complete polymerization reactions but lose theirsoftening ability at high temperatures (≥ 100°C) and are prone to cracking.Similar to alkali-activated geopolymers, acid-activated geopolymers exhibit good fireresistance thanks to their intumescence characteristics upon heating. The main factorinfluencing such property is the P/Al ratio. When the P/Al ratio is high (≥ 0.74), a largeamount of slightly condensed phosphorus is generated, which dehydrates and condensesupon heating, causing the material to soften and expand. Due to this intumescencecharacteristic, geopolymers with low Al/Si (alkaline geopolymer) or high P/Al (acidicgeopolymer) are promising fire-resistant material
2
Pinto, Tiago Manuel Carvalho Gomes. "Estudo de tintas intumescentes na protecção de elementos estruturais em condições de incêndio." Master's thesis, Instituto Politécnico de Bragança, Escola Superior de Tecnologia e de Gestão, 2008. http://hdl.handle.net/10198/2080.
Full textAbstract:
Para satisfazer as exigências regulamentares estruturais de segurança contra incêndios, as estruturas metálicas
podem utilizar mecanismos de protecção passiva (utilização de tintas intumescentes). Trata-se de um material reactivo
que altera as suas propriedades e características termo-físicas, aumentando a resistência térmica da protecção. A
resistência ao fogo das estruturas metálicas aumenta com a utilização deste mecanismo de protecção. A metodologia
actual para verificação de segurança, preconizada nas normas europeias (Eurocódigos), não tem em consideração o
aumento da espessura do material protector, nem a variação das propriedades térmicas e físicas com o aumento da
temperatura, não descrevendo o comportamento real deste material, em situação de incêndio. Pretende-se com este
trabalho efectuar a caracterização do comportamento deste tipo de materiais, determinando as suas principais
características, utilizando metodologias experimentais e numéricas. Pretende-se ainda efectuar um estudo paramétrico
dos factores que influenciam esse comportamento, nomeadamente, a espessura de protecção, a dimensão do substrato,
o fluxo de calor /temperatura e a taxa de aquecimento.
Foi construída uma instalação experimental para realização de ensaios à escala reduzida, com o objectivo de
determinar o comportamento de diferentes elementos sujeitos à acção do fogo. A característica inovadora deste
trabalho está reflectida na apresentação de uma nova solução de cálculo simplificado para determinação da evolução
da temperatura em perfis metálicos protegidos com tinta intumescente em situação de incêndio. The increasing fire protection requirements for elements or structures may involve the employment of
passive protection measures. The knowledge of reaction materials, such as intumescent paints, requires the physical
and thermal material characterization under fire conditions. Due to the high conductivity of steel section profiles and
the reduction of load bearing capacity associated, intumecent paint plays an important role in reducing temperature on
steel. This protection mechanism is responsible for increasing thermal resistance, rising structural fire resistance time.
The current methodology for safety verification, prescribed in European standards, does not take into consideration
the increase of thickness protection material, neither thermal nor physical properties development with temperature.
This method does not express the real protection behavior under fire conditions. Numerical and experimental tests are
expected to assess the intumescent volume expansion and thermal conductivity.
An experimental set-up will be installed for test reduced-scale specimens to assess the material performance.
The innovative characteristic of this work is reflected in the presentation of a new simplified solution method
to obtain temperature development for protected steel members with intumescent paint, under fire conditions
3
Pereira, Alexandre Augusto. "Desenvolvimento experimental e numérico do comportamento de tintas intumescentes na protecção de elementos estruturais em condições de incêndios." Master's thesis, Instituto Politécnico de Bragança, Escola Superior de Tecnologia e de Gestão, 2009. http://hdl.handle.net/10198/2034.
Full textAbstract:
Para satisfazer as exigências regulamentares estruturais de segurança contra incêndios, as estruturas
metálicas podem utilizar mecanismos de protecção passiva (utilização de tintas intumescentes). Trata-se de um
material reactivo que altera as suas propriedades e características termo-fisicas aumentando a resistência térmica
da protecção. A resistência ao fogo das estruturas metálicas aumenta com a utilização deste mecanismo de
protecção. A metodologia actual para a verificação de segurança preconizada nas normas europeias
(Eurocódigos), não tem em consideração o aumento da espessura do material protector, nem a variação das
propriedades térmicas e físicas com o aumento da temperatura. Com este trabalho pretende-se efectuar a
caracterização do comportamento deste tipo de materiais, determinando as suas principais características,
utilizando metodologias experimentais.
Foram realizados ensaios experimentais em perfis metálicos com diferentes secções e diferentes valores
de massividade. Foi caracterizado o perfil de intumescência para cada secção e medida a evolução da
temperatura de cada perfil em diferentes pontos. The increasing fire protection requirements for elements or structures may involve the employment of
passive protection measures. The knowledge of reaction materials, such as intumescent paints, requires the
physical and thermal material characterization under fire conditions. Due to the high conductivity of steel section
profiles and the reduction of load bearing capacity associated, Intumescent paint plays an important role in
reducing temperature on steel. This protection mechanism is responsible for increasing thermal resistance, rising
structural fire resistance time.
The current methodology for safety verification, prescribed in European standards, does not take into
consideration the increase thickness protection material, neither thermal nor physical properties development
with temperature. This method does not express the real protection behavior under fire conditions. Experimental
tests are expected to access the Intumescent volume expansion and thermal conductivity.
Different steel section profiles and section factors were experimentally tested. The intumescence was
characterized for each section and temperature evolution was measured in different points.
4
Deogon, Malkit Singh. "A study of intumescent coatings." Thesis, Brunel University, 1989. http://bura.brunel.ac.uk/handle/2438/6297.
Full textAbstract:
Intumescent coatings are used in the field of fire protection to prevent certain construction elements reaching the critical temperatures at which excessive damage would. occur, thus avoiding premature structural collapse. The studies presented in this thesis have been directed towards an understanding of intumeseent coatings and the process of intumescence. The kinetics and mechanism of intumeseence are discussed. The behaviour of the raw materials used in the preparation of intumeseent coatings, was studied at elevated temperatures using thermal analytical techniques, and new formulations were developed. These formulations were examined In the laboratory using various screening tests and were also subjected to a large scale hydrocarbon fire test alongside other commercially-avallable coatings. A simplified coating formulation with the minimum of ingredients required to produce good intumescent properties was developed. This formulation was subjected to various heat-radiation intensities using an ISO ignitablilty apparatus. The behaviour of the intumescence, process observed was explained by a simple theoretical model. The model of Buckmasterv Anderson and Nachman was used and several new results were derived. In particular a relationship was derived giving the time taken for the temperature at the inner surface of the coating to reach a given value. The durability of the newly-developed intumescent coatings, and methods of improving it, were also investigated.
5
Knott, Paula T. A. "Intumescent formulations incorporating melamine phosphate." Thesis, Aston University, 1988. http://publications.aston.ac.uk/9707/.
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Once familiar with the fire test rig constructed by M Kay, and modified to allow incorporation of both video and computer facilities, Melamine Phosphate production was scaled up from small to large laboratory scale, and then commercial scale production was considered. Samples produced at each stage were compared analytically, visually and in fire testing. The separation and drying stages on a commercial scale lay unresolved practically, due to lack of test facilities. Different cure regimes for the Araldite MY753 and Versamid system were investigated along with weathering tests and cured samples. Surface priming is suggested for large scale application, though on a small scale a clean unprimed surface was thought sufficient. Some samples heat, aired, cracked at the edges but remained bonded on fire testing. An intumescent sample containing Melamine Phosphate, Araldite and Versamid could not be applied to a vertical surface successfully, the viscosity had to be increased to allow application and curing, various additives were tested, two successful ones being fumed silica and a solvent, isopropanol. The low percentages fumed silica used was incorporated into the sample and the viscosity and fire test results compared with a `standard sample'. An expanding graphite incorporated into a standard sample made mixing and application increasingly difficult, due to the lubricating affect of graphite, but the char produced was a good quality, stable char. A suitable formulation could now be mixed, applied and cured, and assuming no adverse interaction between the additives would protect the sample in the event of a fire.
6
Kang, Sungwook. "Thermal-structural behaviour of inorganic intumescent system." Thesis, Ulster University, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701059.
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This work discusses the thermal-structural behaviour of an 'inorganic'based intumescent coating. On exposure to heat, this fire-retardant system undergoes particular physical phenomena: (i) Thermo-chemical decomposition reactions; (ii) Formation of numerous micro-scale pores in its internal structure; (iii) Geometrical volume (thickness) expansions; (iv) Variations in its thermal boundaries. These simultaneous occurrences interact with each other's progressions with time. In order to evaluate the coating's thermal insulation performance and to optimise its performance, this study aims to clearly interpret the combined thermal-structural behaviour. This research program is constructed in four stages: • To identify the thermo-kinetic and -physical characteristics of the polymer compound, this work analyses the experimental data, obtained from Thermogravimetric Analysis, Differential Scanning Calorimetry, Electronic Furnace, and Cone Calorimeter tests; • To accurately quantify the net heat absorbed by the swelling specimen tested with the cone calorimetry, this study investigates (i) the irradiance intensification on the sample's top surface moving toward the heater, (ii) the heat transfer through the surface area of its perimeter being progressively extended, (iii) the convective fluid motions driven in testing and the corresponding coefficients, and (iv) the radiant mechanism generated in testing and the corresponding radiative properties; • To quantitatively assess the thermal insulation performance of the coating, this work numerically simulates the heat transfer mechanism through its porous structure, and analyses individual contributions of the component modes of heat transfer, by adopting 'effective' thermal conductivity; • To comprehensively explain the thermal-structural behaviour of the coating, this study proposes a series of sequential steps of mass and volume changes as a function of temperature, and numerically simulates the process of intumescence. All the findings gained from the previous three stages are applied in this simulation, which is verified by comparison with the experimental data. From this work, it can be identified that the performance of this refractory product is significantly affected by (i) endothermic water vaporisation with dehydration and dehydroxylation, (ii) effective thermal conductivity of its multi-cellular structure, (iii) length of the heat penetration path across its expanding volume, and (iv) radiant heat emission on its heated surfaces. The interacting behaviour of the inorganic-based intumescent coating is systematically analysed, from microscopic thermo-kinetic characteristics to macroscopic behaviours in relation to heat transfer and thermal expansion, in this study. Hence, it can contribute to further studies on intumescent-type materials and their practical development.
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Triantafyllidis, Zafeirios. "Structural enhancements with fibre-reinforced epoxy intumescent coatings." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29514.
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Epoxy intumescent coatings are fire protection systems for steel structural elements that are widely used in applications that protection from severe hydrocarbon fires is required, such as oil and gas facilities. These polymer coatings react upon heating and expand into a thick porous char layer that insulates the protected steel element. In the typical fire scenarios for these applications, the intumescent coatings must resist very high heat fluxes and highly erosive forces from ignited pressurised gases. Hence, continuous fibre reinforcement is embedded in the thick epoxy coating during installation, so as to ensure the integrity of the weak intumesced char during fire exposure. This reinforcement is typically in the form of a bidirectional carbon and/or glass fibre mesh, thus under normal service conditions a fibre-reinforced intumescent coating (FRIC) is essentially a lightly fibre-reinforced polymer (FRP) composite material. This thesis examines the impacts of embedded high strength fibres on the tensile behaviour of epoxy intumescent materials in their unreacted state prior to fire exposure, and the potential enhancements that arise in the structural performance of elements protected with FRICs. An experimental programme is presented comprising tensile coupon tests of unreacted intumescent epoxies, reinforced with different fibre meshes at various fibre volume fractions. It is demonstrated that the tensile properties of FRICs can be enhanced considerably by including increasing amounts of carbon fibre reinforcement aligned in the principal loading direction, which can be tailored in the desired orientation on the coated structural members to enhance their load carrying capacity and/or deformability. An experimental study is presented on coated intact and artificially damaged I-beams (simulating steel losses from corrosion) tested in bending, demonstrating that FRICs can enhance the flexural response of the beams after yielding of steel, until the tensile rupture of the coatings. An analytical procedure for predicting the flexural behaviour of the coated beams is discussed and validated against the obtained test results, whereas a parametric analysis is performed based on this analytical model to assess the effect of various parameters on the strengthening efficiency of FRICs. The results of this analysis demonstrate that it is feasible to increase the flexural load capacity of thin sections considerably utilising the flexural strength gains from FRICs. Finally, a novel application is proposed in this thesis for FRICs as a potential system for structural strengthening or retrofitting reinforced concrete and concrete-encased steel columns by lateral confinement. An experimental study is presented on the axial compressive behaviour of short, plain concrete and concrete-encased structural steel columns that are wrapped in the hoop direction with FRICs. The results clearly show that epoxy intumescent coatings reinforced with a carbon fibre mesh of suitable weight can provide lateral confinement to the concrete core resisting its lateral dilation, thus resulting in considerable enhancements of the axial strength and deformability of concrete. The observed strengthening performance of the composite protective coatings is found to be at least as good as that of FRP wraps consisting of the same fibre reinforcement mesh and a conventional, non-intumescent epoxy resin. The predictive ability of existing design-oriented FRP confinement models is compared against the experimental results, and is found to be reasonably precise in predicting the peak strength of the tested columns, hence existing models appear to be suitable for design and analysis of column strengthening schemes with the proposed novel FRIC system. The research presented herein shows clearly that FRICs have a strong potential as alternative systems for consideration in the field of structural strengthening and rehabilitation, since they can provide substantial enhancements in the load carrying capacity for both applications considered. At the same time FRICs can thermally protect the underlying structural elements in the event of a fire, by intumescing and charring, thus potentially eliminating the need for additional passive fire protection that is common with conventional fire-rated FRP wrapping systems. Although this thesis provides a proof-of-concept for use of the proposed novel FRICs as structural strengthening materials, considerable additional research is particularly required to study their fire protection performance when applied to concrete substrates, to make use of the proposed hybrid functionality with confidence.
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Fayokun, Ranti. "Study of the thermal behaviours of intumescent silicate materials." Thesis, University of Greenwich, 2005. http://gala.gre.ac.uk/6167/.
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The fire retardant properties of inorganic silicate based materials were characterised by Thermal, Infrared (IR), Karl Fischer (KF), Mass Spectrometry (MS) and Cone Calorimetry (CC) techniques. Scanning Electron Microscopy (SEM) was also employed to study the sample morphologies. In this study, spectral data were analysed by multivariate Target Factor Analysis (TFA) to determine the relative evolution profiles of selected fire gases. A combination of the gas evolution profiles and further numerical treatment of the thermal characterisation data provided a novel set of protocols to assess the high temperature behaviour of the fire protective silicate materials. In the context of this work, the study discusses the structure-property relationships of the silicates, identifies the degradation stages and elucidates the processes involved during thermal treatment by comparison with mechanistic findings in published literature. The following conclusions were drawn. Five transitions were detected by thermal analyses, which correspond to; i) the evolution of water and flammable species ii) the rearrangement of interstitial ions and water molecules iii) the evaporation of water of condensation from silanol groups iv) the decomposition of samples and i) structural rearrangement. Cone calorimetry studies revealed that samples with low polyol (P) and high SiO2:Na2O weight ratio (WR) exhibited very low heat release rates (HRR) and vice versa. It was observed that in general, low polyol content and high SiO2:Na2O WR enhanced fire resistivity. This provided a better understanding of the thermo-degradation patterns of samples and the underlying chemistry influencing the performances of the inorganic silicate based materials.
9
Cirpici, Burak Kaan. "Simulating the expansion process of intumescent coating fire protection." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/simulating-the-expansion-process-of-intumescent-coating-fire-protection(6de4a5f5-0fb7-4d28-a083-9c783c692e4c).html.
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The expansion ratio (defined as the ratio of the expanded thickness to the original thickness) of intumescent coatings is the most important quantity that determines their fire protection performance. This thesis explores two possible methods of predicting intumescent coating expansion: an analytical method, and a detailed numerical simulation method using Smoothed Particle Hydrodynamics (SPH).The analytical method is based on a cell-model and predicts bubble growth due to pressure increase in viscous liquid with constant viscosity. It has been extended to non-uniform temperature field and temperature-dependent viscosity of intumescent melt. Accuracy of this extended analytical method is assessed by comparison against the cone calorimeter and furnace fire tests on intumescent coating protected steel plates with different intumescent coating thicknesses, steel plate thicknesses, and heating conditions. The extended analytical method is then used to investigate how intumescent coating expansion and intumescent coating effective thermal conductivity are affected by changing the coating thickness, the steel thickness and the fire condition (including smouldering fire). The main conclusion is that the expansion ratio decreases as the rate of heating increases. Therefore, the intumescent coating properties obtained from the Standard fire exposure may be safely used for slower realistic fires, but would produce unsafe results for faster fires. The second method explores the potential of a meshless numerical simulation: Smoothed Particle Hydrodynamics (SPH). SPH modelling of intumescent coating expansion has been implemented using the SPHysics FORTRAN open-source code as a platform. To check the validity of this modelling method, the modelling results are compared against theoretical solutions for surface tension (Young-Laplace theorem), and available numerical and analytical solutions for bubble expansion. A new algorithm for representing the mass transfer of gas into the bubble using SPH particle insertion and particle shifting scheme is presented to simulate the bubble expansion process. Close agreement with an analytical solution for the initial bubble expansion rate computed by SPH is obtained. Whilst this research has demonstrated the potential of using SPH to numerically simulate intumescent coating expansion, it has also revealed significant challenges that should be overcome to make SPH a feasible method to simulate intumescent coating expansion. The main challenges include:• Simulating gas-polymer flows when expansion is occurring where there are vastly different properties of these two fluids with a density ratio of about 1000. This high density ratio may easily cause numerical pressure noise, especially at the liquid-gas interface.• Extremely high computational cost necessary to achieve sufficient accuracy by using a large number of particles (higher resolution), especially for the multi-phase SPH program, and very small time step for the lighter fluid (air). • The behaviour of intumescent coatings involves expansion ratios on the order of 10-100 with thousands of bubbles which grow, merge and burst. Based on the results of this exploratory research, future improvements are outlined to further develop the SPH simulation method.
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Muller, Maryska. "Systemic approach of the synergism in flame retarded intumescent polyurethanes." Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10109/document.
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L’objectif de ce travail de thèse est de mettre en évidence et de comprendre le mécanisme de synergie observé au niveau des propriétés retard au feu de polyuréthanes (PUs) intumescents par l’ajout de nanoparticules (NPs). En effet, l’addition de polyphospha te d’ammonium (APP) dans une matrice PU conduit à une amélioration de ses propriétés retard au feu. La substitution d’une petite quantité d’APP par des NPs (MgO, SiO2, octamethyl polyhedral oligomeric silsesquioxanes (OMPOSS) et or) conduit de plus à un phénomène de synergie. Il a été montré que la nature et la quantité de NPs jouent un rôle important sur les propriétés retard au feu et sur le mécanisme de protection. L’étude de la stabilité thermique des différents systèmes a premièrement mis en évidence une stabilisation entre l’APP et les NPs à l’exception de l’OMPOSS. Il a donc été proposé que la synergie intervienne en phase condensée où diverses réactions chimiques, caractérisées par RMN du solide, ont lieu lors de la dégradation des matériaux entrainant la formation d’une barrière protectrice intumescente. Les propriétés de cette barrière, telles que sa conductivité thermique, son expansion et sa morphologie, ont été étudiés dans un second temps à l’aide de techniques spécifiques développées dans le cadre de cette étude (en particulier la tomographie). Ces propriétés ont été reliées à la meilleure protection observée pour le système contenant l’APP et les NPs. La résistance mécanique de barrières intumescentes développées dans différentes conditions a finalement été étudiée mais n’intervient pas dans le mécanisme de synergie<br>The purpose of this Ph.D work is to present and to understand the synergy observed in the fire performances of intumescent polyurethane (PU) formulations by the addition of nanoparticles (NP). Indeed, it was shown that the addition of ammonium polyphosphate (APP) in PU leads to interesting fire properties that can be enhanced substituting a small amount of APP by NPs (MgO, SiO2, octamethyl polyhedral oligomeric silsesquioxanes (OMPOSS) and gold). The nature and content of the NPs play an important role on the fire retardant properties and mechanisms. First, a thermal stabilization was observed between APP and the different NPs except OMPOSS. The synergy mechanism was thus attributed to a condensed phase action where a range of chemical species, characterized by solid state NMR, are created upon heating the material in different conditions. The char properties, such as thermal conductivity, expansion and morphology, were then characterized using novel techniques (in particular tomography). It was shown that they are linked with the thermal barrier effect of the residual material explaining the good fire properties obtained when combining APP and NPs. The mechanical strength of chars developed in different conditions was also investigated but do not play a significant role on the synergy mechanism
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Yuan, Jifeng. "Intumescent coating performance on steel structures under realistic fire conditions." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498956.
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Intumescent coating, as a new generation of fire proof material, has obvious advantages over traditional fire protection materials. The applications of intumescent coating are widely ranged and it has become dominant in the fire engineering market. However, the present method of assessment in EN 13381 Part 4 is not suitable for applications of intumescent coating under realistic fire conditions, because intumescent coating behaviour is not only temperature dependent, but also fire exposure dependent. The failure of currently available method to give accurate predictions of intumescent coating thermal performance motivated this research. Against this background, a 1-0 mathematical model has been established to consider chemical kinetics, mass and energy conservation, and heat transfer through solid and gas phases. The model couples the degradation of three basic components (inorganic acid source, blowing agent, and charring material) with a variable volume system. Basic volatile mass transfer and simplified bubbling mechanisms have been described in assistance to calculate the non-linear distribution of temperature along the coating thickness. The model is presented in terms of Finite Difference Method (FOM) equations and is solved using FORTRAN programming. Then, an extensive sensitivity study has been carried out to identify most influential parameters among a large number of material input data required by the mathematical model. A. The activation energies of the blowing agent and the charring material, the maximum expansion coefficient and the final bubble size have been shown to have the most influence on the predicted steel temperature results. To assess the influence of different pore size distributions, Finite Element simulations (ABAQUS) were performed. The results of this numerical study indicate that, given the same porosity, the overall thermal conductivity of the porous structure is very close to that with uniform distribution of pores of the dominant size. This strongly suggests that, given the difficulty of obtaining precise pore size distribution, it is practically acceptable to treat an intumescent coating as having a uniform distribution of pores of the same size. A number of cone-calorimeter tests have been carried out with different coating thicknesses, steel substrate thicknesses, and external heat fluxes. The investigation focused on how to extract key parameters of the model from limited number of experimental tests, and how to make use of the model in different applications. The estimated input parameters are able to predict all the cone calorimeter tests to match the experimental measurement with reasonably good agreement, which demonstrates the feasibility of the modelling approach. Finally, to provide comprehensive validation, both standard and parametric furnace fire tests have been performed. The key parameters of chemical kinetics and intumescent char bubble size were determined experimentally. The TGA test data were used to obtain the major intumescent coating component fractions and the various chemical kinetics constants. The mathematical model described in this study is able to accurately predict both the standard fire test results and the parametric fire test results. The only requirement is that the final expansion coefficient of the intumescent coating should be provided as input data.
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Shell, Adrian. "An investigation of intumescent pyrotechnics : synthetic studies towards FK506 and morphine." Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.523559.
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Anderton, Edwyn Christopher Morgan. "Relationships between polymer-additive molecular structure and intumescent flame retardant behaviour." Thesis, Sheffield Hallam University, 1990. http://shura.shu.ac.uk/19277/.
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This thesis describes studies of the relationship between the molecular structure of a range of organophosphorus-based polymer additives and their ability to confer intumescent flame retardant properties on the resulting polymers. The development of intumescent fire retardants is discussed along with the principles of flame retardancy in general. Much of the work centred around the chemistry of a key starting material, pentaerythritol phosphate (PEPA). This compound was found to be less reactive than expected, due to a combination of its neopentyl type structure and the electron withdrawing effect of the phosphoric ester functionality. Various derivatives of PEPA were synthesised, most containing reactive functional groups which facilitated future development of the compound. The derivatives containing no reactive groups were investigated for their intumescent behaviour in their own right. Derivatives of PEPA containing an acidic functionality were utilised in the production of intumescent salt systems using cations with a high nitrogen content in the form of s-triazines. The most promising was the trimethylolmelamine salt of a bis-PEPA derivative of phosphoric acid, which, on testing, proved to be more effective than the current "state of the art" intumescent additive. Metal salts of acidic PEPA-derivatives were also investigated. Derivatives of PEPA containing a carbon-carbon double bond were investigated for their potential to polymerise and thus form more stable additives. Only one such polymer was successfully synthesised, that being poly (PEPA methacrylate). Despite being non-intumescent, due to its high thermal stability this polymer has potential as a flame retardant additive. The monomer was found to copolymerise with methyl methacrylate to form a polymer of high thermal stability. When investigating the relationship between the molecular structure of the compounds developed and their intumescent behaviour, it was observed that only compounds containing an ionisable hydrogen atom exhibited intumescent decomposition on pyrolysis.
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Kim, Hyungjun. "Experimental investigation of the thermo-mechanical response of Intumescent Mat Material." Connect to resource, 2000. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1132171607.
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Costa, Daniel Anísio do Nascimento. "Estudo do processo de extração do óleo da Macaúba (Acrocomia Intumescens." Universidade Federal de Alagoas, 2016. http://www.repositorio.ufal.br/handle/riufal/1584.
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The macaúba-barriguda (Acrocomia intumescens) is a palm tree species with common occurrence in the northeastern forest zone. The fruit is widely consumed in natura by the population. Both the pulp and the almond produce oils with unstudied properties. The objective of this study was to analyze the efficiency of macauba's almond and pulp oil extraction process through mechanical pressing and solvent extraction (leaching) with the help of an experimental design. The biometric characterization of the fruits was performed with the aid of a pachymeter and analytical balance. The pulp was extracted with a knife after drying at 60 ° C and the almonds were removed through a mechanical press and dried at the same temperature until reaching the constant mass. In mechanical extraction by the hydraulic press were used these pressures: 330; 412.5; 495 and 577.5 kgf/cm². For the leaching, a complete 23 factorial design was elaborated. Three variables were used: extraction time, solvent and extraction method, in two levels of control: inferior and superior, the time being defined in 3 hours and 6 hours, the solvent In hexane and isopropanol and the method of extracting the oil in standard soxhlet and continuous extraction. The factorial design of the pulp and almond oil extraction showed approximately similar results, being the time of extraction the most significant factor, followed by the solvent and the other interactions. The pressure extraction of 577.5 kgf/cm² showed the highest amount of extracted oil with 24.1 grams of oil in 100 g of pulp and 21.7 grams of oil for the same initial mass of almond. The highest oil yield obtained in the experimental design was higher than 31% on the almond using continuous extraction, with isopropanol as the solvent for 6 hours of extraction, and higher than 38% for the pulp under the same conditions. The extracted oils were characterized according to the humidity, density, pH, and acidity index. The oil almond proved suitable to use for purposes of biodiesel production according to the desired specifications. The exception was the density, which was higher than indicated. The combination of mechanical extraction and solvent extraction at lower pressures proved to be a good option for oil content, presenting higher results than those obtained through mechanical pressure at higher pressures.<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico<br>A macaúba-barriguda (Acrocomia intumescens) é uma espécie de palmeira de comum ocorrência na Zona da Mata nordestina, com o fruto bastante consumido in natura pela população. Tanto sua polpa quanto sua amêndoa produzem óleos com propriedades pouco estudadas. O objetivo deste trabalho foi analisar a eficiência do processo de extração do óleo da amêndoa e da polpa da macaúba através de prensagem mecânica e da extração por solvente (lixiviação) com auxílio de um planejamento experimental. A caracterização biométrica dos frutos foi realizada com o auxílio de paquímetro e balança analítica. A polpa foi extraída, após secagem a 60ºC, com uma faca, e as amêndoas foram retiradas através de uma prensa mecânica e secas na mesma temperatura, até atingirem massa constante. Na extração mecânica por prensa hidráulica, foram utilizadas as pressões: 330; 412,5; 495 e 577,5 kgf/cm². Para a lixiviação foi elaborado um planejamento fatorial 23 completo, onde foram utilizadas três variáveis: tempo de extração, solvente e método de extração, em dois níveis de controle, inferior e superior, sendo o tempo definido em 3 horas e 6 horas, o solvente em hexano e isopropanol e o método de extração do óleo em soxhlet padrão e extração contínua. Os planejamentos fatoriais da extração do óleo da polpa e da amêndoa apresentaram resultados aproximadamente semelhantes, sendo o tempo de extração o fator mais significante, seguido pelo solvente e as demais interações. A extração na pressão de 577,5 kgf/cm² apresentou a maior quantidade de óleo extraído, com 24,1 gramas de óleo em 100 g de polpa e 21,7 gramas de óleo para a mesma massa inicial de amêndoa. O maior rendimento em óleo obtido nos planejamentos experimentais foi superior a 31% para a amêndoa, utilizando a extração contínua, com o isopropanol como solvente por 6 horas de extração, e superior a 38% para a polpa nas mesmas condições. Os óleos extraídos foram caracterizados de acordo com a umidade, densidade, pH e índice de acidez. O óleo da amêndoa se mostrou propício a utilização para fins de produção de biodiesel, de acordo com as especificações desejadas, com exceção da densidade, a qual foi superior ao indicado. A combinação de extração mecânica e extração por solvente nas pressões inferiores se mostrou boa opção quanto ao teor de óleo obtido, apresentando resultados superiores aos encontrados através da pressão mecânica para as pressões superiores.
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Ciret, Jérémy. "Investigation of intumescent coatings for fire protection : application to jet-fire." Thesis, Lille 1, 2010. http://www.theses.fr/2010LIL10187/document.
Full textAbstract:
Cette étude s’intéresse aux comportements de 4 peintures intumescentes développées pour protéger des plateformes offshores et susceptibles de résister aux « jet-fires ». Un jet-fire peut intervenir sur un site pétrochimique suite à une fuite d’hydrocarbures sous pression et causer de sérieux dommages de part la chaleur dégagées et surtout la quantité de mouvement générées. Les aspects physiques et chimiques de ces formulations ont été développés permettant de mettre en avant les effets du pentaérythritol sur le comportement viscoélastiques et le processus d’intumescence. Par diffraction des rayons X et par RMN à l’état solide, nous avons montré les interactions entre ammonium et polyphosphate et différentes sources de carbones (pentaérythritol, dipentaérythritol, réseau époxyde) permettant la formation d’un char. Les résidus phosphorés réagissent ensuite avec TiO2 pour former une structure cristalline TiP2O7 suspectées d’améliorer la résistance au feu et la résistance mécanique du char. Des tests feu ont confirmés ces améliorations. Dans un dernier chapitre nous avons développé un test permettant de reproduire à l’échelle laboratoire les phénomènes radiatifs et convectifs du jet-fire. Les premiers résultats ont montré de bonnes corrélations entre les observations faites à grande échelle et celles réalisées au laboratoire<br>The aim of this study is to understand and to explain behaviours exhibited by four epoxy based intumescent formulations used on offshore platforms facing to jet-fire. A jet-fire is a turbulent diffusion flame resulting from the combustion of a fuel continuously released with some significant momentum. It represents a significant element of the risk on offshore installations. Regarding the formulation studied, we have developed three approaches. Firstly, the visco-elastic behaviour and mechanical resistance of the formulations have been investigated. The results show that pentaerythritol causes a viscosity decrease at lower temperature that appears as prejudicial to maintain efficient char on steel substrate. In a second part, chemical evolutions of the intumescent formulation have been determined thanks to solid-state NMR and X-Ray diffraction. Interactions between ammonium polyphosphate and respective carbon sources present in formulations have been assumed, yielding to the formation of char and production of phosphorus residues. Then these phosphorus residues react at high temperature with TiO2 to form a crystalline structure TiP2O7 suspected to enhance mechanical properties and flame retardant performance. In a last part, furnace fire tests confirm this enhancement. Furthermore a new small-scale experimental setup is developed mimicking large scale jet-fire resistance test in order to obtain rapidly and at low cost reliable behaviours of a large number of formulations facing to high load mixing radiative heat and flame impact. First results have been correlated with the large-scale ones and different geometries have been considered
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Hansupo, Nittaya. "Fundamental aspects of intumescent systems for fire protection of steel structures." Thesis, Lille, 2018. http://www.theses.fr/2018LIL1R005.
Full textAbstract:
Le but de ce travail de thèse est d’obtenir une compréhension des mécanisme d’action des revêtements intumescents à base d’époxy afin de fournir des perspectives pour le développement de nouveaux systèmes de protection contre le feu. La formulation intumescente est un système très complexe. Ce travail se concentre en particulier sur les composants clés dont la compréhension des mécanismes d’action était absente. Tout d’abord, les mécanismes d’action des borates ont été étudiés en incluant des modifications chimiques et thermo-physiques; la combinaison des résultats obtenus sous différents aspects permet de comprendre son mode d’action. D’un côté, les borates en particulier l’acide borique ont été mentionnés comme Cancérogènes, Mutagènes, Reprotoxiques (CMR); la substitution de ces composants est nécessaire. Les résultats soulignent le rôle important et la réactivité élevée du zinc (de borate de zinc), ce qui suggère le développement de nouveaux systèmes en incorporant un composé à base de zinc au lieu du borate du zinc. Deuxièmement, l’effet du CaCO3 sur les propriétés de protection contre le feu et son mécanisme d’action dans le revêtement intumescent ont été examinés. L’ajout de CaCO3 améliore les propriétés de protection au feu et d’adhérence/cohérence du revêtement et son mécanisme d’action était justifié. De plus, plusieurs carbonates (MgCO3, ZnCO3, Na2CO3, K2CO3) en tant qu’ingrédient intumescent ont également été examinés. L’utilisation de MgCO3 comme ingrédient intumescent est favorable pour les propriétés de protection contre le feu du revêtement ainsi que pour l’utilisation de CaCO3. Dans ce travail, les mécanismes d’action des borates et des carbonates ont été étudies. Les résultats suggèrent le développement de nouveaux systèmes utilisant des ingrédients alternatifs tels que le composé à base de zinc ou MgCO3<br>The goal of this PhD work is to get an insight into the mechanisms of action of epoxy based intumescent coating to be able to provide the outlooks for the development of novel systems of higher protection against fire. The intumescent formulation is highly complex system. This work focuses particularly on the key components of which the understanding of the mechanisms of action is still lacking. Firstly, the mechanisms of action of borates were investigated in both chemical and thermo-physical modifications; the combination of the results obtained from different aspects allows drawing its mode of action. On the one hand, borates in particular boric acid have been mentioned to be Carcinogenic, Mutagenic, Reprotoxic (CMR); the substitution of these important intumescent components are necessary. The results point out the important role and high reactivity of zinc (i.e. from zinc borate), this suggests the development of novel systems by incorporating zinc based compound instead of zinc borate. Secondly, the effect of CaCO3 on fire protective properties and its mechanism of action in intumescent coating were examined. The addition of CaCO3 improves the fire protective properties and adhesion/cohesion of the coating and its mechanism of action was fully justified. Additionally, various carbonates (i.e. MgCO3, ZnCO3, Na2CO3, K2CO3) as intumescent ingredient were also examined. The use of MgCO3 as intumescent ingredient is beneficial for the fire protective properties of the coating as well as the use of CaCO3. In this work, the mechanisms of action of borates and carbonates were fully examined. The results suggest the development of novel systems with using the alternative ingredients such as zinc-based compound or MgCO3
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Ciret, Jérémy. "Investigation of intumescent coatings for fire protection : application to jet-fire." Electronic Thesis or Diss., Lille 1, 2010. http://www.theses.fr/2010LIL10187.
Full textAbstract:
Cette étude s’intéresse aux comportements de 4 peintures intumescentes développées pour protéger des plateformes offshores et susceptibles de résister aux « jet-fires ». Un jet-fire peut intervenir sur un site pétrochimique suite à une fuite d’hydrocarbures sous pression et causer de sérieux dommages de part la chaleur dégagées et surtout la quantité de mouvement générées. Les aspects physiques et chimiques de ces formulations ont été développés permettant de mettre en avant les effets du pentaérythritol sur le comportement viscoélastiques et le processus d’intumescence. Par diffraction des rayons X et par RMN à l’état solide, nous avons montré les interactions entre ammonium et polyphosphate et différentes sources de carbones (pentaérythritol, dipentaérythritol, réseau époxyde) permettant la formation d’un char. Les résidus phosphorés réagissent ensuite avec TiO2 pour former une structure cristalline TiP2O7 suspectées d’améliorer la résistance au feu et la résistance mécanique du char. Des tests feu ont confirmés ces améliorations. Dans un dernier chapitre nous avons développé un test permettant de reproduire à l’échelle laboratoire les phénomènes radiatifs et convectifs du jet-fire. Les premiers résultats ont montré de bonnes corrélations entre les observations faites à grande échelle et celles réalisées au laboratoire<br>The aim of this study is to understand and to explain behaviours exhibited by four epoxy based intumescent formulations used on offshore platforms facing to jet-fire. A jet-fire is a turbulent diffusion flame resulting from the combustion of a fuel continuously released with some significant momentum. It represents a significant element of the risk on offshore installations. Regarding the formulation studied, we have developed three approaches. Firstly, the visco-elastic behaviour and mechanical resistance of the formulations have been investigated. The results show that pentaerythritol causes a viscosity decrease at lower temperature that appears as prejudicial to maintain efficient char on steel substrate. In a second part, chemical evolutions of the intumescent formulation have been determined thanks to solid-state NMR and X-Ray diffraction. Interactions between ammonium polyphosphate and respective carbon sources present in formulations have been assumed, yielding to the formation of char and production of phosphorus residues. Then these phosphorus residues react at high temperature with TiO2 to form a crystalline structure TiP2O7 suspected to enhance mechanical properties and flame retardant performance. In a last part, furnace fire tests confirm this enhancement. Furthermore a new small-scale experimental setup is developed mimicking large scale jet-fire resistance test in order to obtain rapidly and at low cost reliable behaviours of a large number of formulations facing to high load mixing radiative heat and flame impact. First results have been correlated with the large-scale ones and different geometries have been considered
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Hansupo, Nittaya. "Fundamental aspects of intumescent systems for fire protection of steel structures." Electronic Thesis or Diss., Université de Lille (2018-2021), 2018. http://www.theses.fr/2018LILUR005.
Full textAbstract:
Le but de ce travail de thèse est d’obtenir une compréhension des mécanisme d’action des revêtements intumescents à base d’époxy afin de fournir des perspectives pour le développement de nouveaux systèmes de protection contre le feu. La formulation intumescente est un système très complexe. Ce travail se concentre en particulier sur les composants clés dont la compréhension des mécanismes d’action était absente. Tout d’abord, les mécanismes d’action des borates ont été étudiés en incluant des modifications chimiques et thermo-physiques; la combinaison des résultats obtenus sous différents aspects permet de comprendre son mode d’action. D’un côté, les borates en particulier l’acide borique ont été mentionnés comme Cancérogènes, Mutagènes, Reprotoxiques (CMR); la substitution de ces composants est nécessaire. Les résultats soulignent le rôle important et la réactivité élevée du zinc (de borate de zinc), ce qui suggère le développement de nouveaux systèmes en incorporant un composé à base de zinc au lieu du borate du zinc. Deuxièmement, l’effet du CaCO3 sur les propriétés de protection contre le feu et son mécanisme d’action dans le revêtement intumescent ont été examinés. L’ajout de CaCO3 améliore les propriétés de protection au feu et d’adhérence/cohérence du revêtement et son mécanisme d’action était justifié. De plus, plusieurs carbonates (MgCO3, ZnCO3, Na2CO3, K2CO3) en tant qu’ingrédient intumescent ont également été examinés. L’utilisation de MgCO3 comme ingrédient intumescent est favorable pour les propriétés de protection contre le feu du revêtement ainsi que pour l’utilisation de CaCO3. Dans ce travail, les mécanismes d’action des borates et des carbonates ont été étudies. Les résultats suggèrent le développement de nouveaux systèmes utilisant des ingrédients alternatifs tels que le composé à base de zinc ou MgCO3<br>The goal of this PhD work is to get an insight into the mechanisms of action of epoxy based intumescent coating to be able to provide the outlooks for the development of novel systems of higher protection against fire. The intumescent formulation is highly complex system. This work focuses particularly on the key components of which the understanding of the mechanisms of action is still lacking. Firstly, the mechanisms of action of borates were investigated in both chemical and thermo-physical modifications; the combination of the results obtained from different aspects allows drawing its mode of action. On the one hand, borates in particular boric acid have been mentioned to be Carcinogenic, Mutagenic, Reprotoxic (CMR); the substitution of these important intumescent components are necessary. The results point out the important role and high reactivity of zinc (i.e. from zinc borate), this suggests the development of novel systems by incorporating zinc based compound instead of zinc borate. Secondly, the effect of CaCO3 on fire protective properties and its mechanism of action in intumescent coating were examined. The addition of CaCO3 improves the fire protective properties and adhesion/cohesion of the coating and its mechanism of action was fully justified. Additionally, various carbonates (i.e. MgCO3, ZnCO3, Na2CO3, K2CO3) as intumescent ingredient were also examined. The use of MgCO3 as intumescent ingredient is beneficial for the fire protective properties of the coating as well as the use of CaCO3. In this work, the mechanisms of action of borates and carbonates were fully examined. The results suggest the development of novel systems with using the alternative ingredients such as zinc-based compound or MgCO3
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Kim, Jae-Su. "Visco-plastic constitutive model development for thermo-mechanical analysis of intumescent mat /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486399451959509.
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Oradei, Stefano <1989>. "Formulation and Study of New Eco-Friendly Intumescent Polylactic Acid Based Materials." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8666/1/Tesi%20dottorato%20in%20chimica%20XXX%20ciclo%20Stefano%20Oradei.pdf.
Full textAbstract:
Polylactic acid (PLA) is a biodegradable and bio-based polymer obtained by polymerization of lactide or lactic acid, both arising from renewable resources like cereals’
starch. Polylactic acid is also a semycristalline thermoplastic polymer and has mechanical properties in between polystyrene and polyethylene terephthalate. In the last decades the interest on this polymer raised very fast and its industrial production increases very rapidly,
in the same way the number of published researches have exponentially increased.
Nowadays the main PLA applications consist on food packaging, disposable tableware, biomedical items and textiles. Future and new PLA applications are focusing towards electric, electronics, and transport field.
The materials for this kind of applications must have good flame resistance properties and several flame and burning tests must be passed before these materials can be applied.
PLA does not have flame resistance properties and burn in air in case of a fire source.
Focusing my research to solve this issue, PLA based materials with different flame retardants additives have been formulated and tested.
Intumescence has been studied as mechanism to achieve good flame resistance properties, and halogen-free, non-toxic and eco-friendly additives have been used trying to maintain
the material biodegradability.
New eco-friendly intumescent polylactic acid based materials have been developed, using low load of halogen-free, not toxic and biodegradable additives (6, 10 and 14%).
Bio-based and biodegradable carbonizing agents such as starch, sorbitol, coffee grounds, glycerol phosphate, cellulose and Kraft lignin have been tested (2%), and V-0 UL94 classification, LOI values over 32% and GWIT over 775°C were archived in presence of different amount of ammonium polyphosphate (4, 8.5%) for all the carbonizing tested.
The presence of zinc borate increased the flame resistance of the materials yielding the lowest total heat release in synergy among all carbonizing agents tested.
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Telford, Christopher Carl. "Development of organic and inorganic intumescent coatings and their use in barrier fabrics." Thesis, Brunel University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268858.
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Kang, Jiyuan. "MORPHOLOGY AND PERFORMANCE CHARACTERIZATION OF INTUMESCENT COATINGS FOR FIRE PROTECTION OF STRUCTURAL STEEL." Case Western Reserve University School of Graduate Studies / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1544112058459729.
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Ouassou, Najib. "Étude d'un nouveau système intumescent "retard au feu" : pyrophosphate diammonique-pentaérythritol : application au polypropylène." Lille 1, 1991. http://www.theses.fr/1991LIL10070.
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Le présent travail concerne le nouveau système d'additifs : pyrophosphate diammonique-pentaérythritol dans le polypropylène isotactique, son objectif est d'apporter une contribution à la connaissance du mécanisme retardant de flamme à partir d'additifs développant un phénomène d'intumescence. Dans un premier temps, l'efficacité des additifs est évaluée. L'association du PY et du PER engendre un effet de synergie qui améliore notablement la propriété «retard au feu» par développement d'un «bouclier thermique» charbonneux et intumescent à la surface de la formulation. Ensuite, l'étude concerne le mécanisme de formation du revêtement charbonneux intumescent à partir des additifs. Dans une première étape, les précurseurs de carbonisation se forment à partir des esters (produits de la réaction entre les additifs) dans le domaine de température 240-280°C. Aux températures supérieures (T>280°C), le matériau intumescent se développe à partir de ces précurseurs principalement par un mécanisme radicalaire. Pour T>350°C, l'évolution de la structure intumescente conduit à un résidu charbonneux non expansé par un phénomène de déshydrogénation, désalkylation-condensation. Finalement, le mécanisme de protection est expliqué par l'existence de réactions entre les produits de la dégradation thermo-oxydante du polymère et les espèces phosphates issues de la dégradation du mélange des additifs. L'étude comparative des formulations (PP-PY-PER) et (PP-polyphosphate d'ammonium-PER) montre que la propriété «retard au feu» est fonction du phosphate utilisé. Les résultats permettent de proposer que les formulations qui développent, lors d'un traitement thermique, un revêtement intumescent doivent, pour être efficaces, générer des espèces acides stables
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Gillet, Mathieu. "Analyse de systèmes intumescents sous haut flux : modélisation et identification paramétrique." Phd thesis, Université d'Angers, 2009. http://tel.archives-ouvertes.fr/tel-00465240.
Full textAbstract:
La protection des structures, matériels et personnels contre les agressions thermiques violentes est une problématique incontournable dans le secteur militaire. Dans ce contexte, les revêtements intumescents, qui ont la propriété de gonfler lorsqu'ils sont soumis à un flux thermique intense, peuvent s'intégrer efficacement parmi les dispositifs de protections traditionnels. Cette étude, menée pour le ministère de la Défense, propose dans un premier temps une étude du comportement des peintures intumescentes et des principales agressions thermiques rencontrées sur le champ de bataille. Leurs effets sur des échantillons revêtus de peinture intumescente sont testés grâce à un moyen d'essai original : le Four Solaire Principal de la Délégation Générale de l'Armement. Dans un second temps, un modèle mathématique 1D basé sur un système d'équations aux dérivées partielles est développé pour décrire le comportement thermique et le gonflement de revêtements intumescents soumis à un flux radiatif. Une analyse de sensibilité est effectuée afin de désigner les paramètres "clés" du modèle (dont les incertitudes influencent particulièrement les résultats). Par la suite, les protocoles d'identification mis en oeuvre pour déterminer ces paramètres sont présentés. Des méthodes inverses basées sur des signaux thermiques périodiques sont utilisées pour identifier la diffusivité thermique des couches vierges et charbonneuse de peinture. En outre, la méthode des gradients conjugués est mise en oeuvre pour l'identification de la conductivité thermique non linéaire de la couche réactive. Enfin, les résultats obtenus sont discutés et les perspectives de l'étude sont présentées.
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Saeed, Hussain. "Studies of the physical aspects of intumescence using advanced diagnostic methods." Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/17839/.
Full textAbstract:
Commercial testing of Intumescent paints can be extremely expensive. There is a need to develop lab scale systems that can cost effectively both study and test intumescent paints under conditions that are closer to commercial and real time fire tests. This research aims to present a strong case for using an impinging flame based rig to test intumescent coatings. The main feature of using flame impingement is the heterogeneous absorption of heat along the wall surface. This property is a great advantage because intumescent paints under complex fire conditions can be simulated more realistically. The heating technique is coupled with advance diagnostics methods to highlight behaviour that has not been observed before. Physical aspects of commercial coatings, under the new setup, are compared to the cone calorimeter – traditional testing setup The process of intumescence was observed through the use of diagnostic techniques such as Schlieren, thermal and digital imaging. Cross sectional area and surface textures were captured using digital images of fully intumesced char samples that revealed distinct internal structures and surface textures. Temperature of the substrate, Tb, was recorded using a thermocouple attached to the back surface of the panel under different heating conditions. Schlieren technique, based on the refraction of light phenomenon, has never been use to examine the physical aspects of intumescence. It helped highlight the interaction between the flame and paint surface. The impingement of non-reactive fuel, at low separations was clearly visible and was responsible for influencing mode shape of the resulting char. The expulsions phenomenon observed using this technique has not been visually observed before. It occurred during the pustule appearance phase offering conclusive evidence that invisible gases escape from the surface of the paint. The measurement of char expansion and its rate of growth whilst engulfed in luminous diffusion flames is a methodology developed using this technique. The results revealed that formulations tested had unique expansion behaviours and growth pattern. Furthermore, an expansion activation temperature (EAT) range with respect to substrate temperature was identified for each formulation, which was found to be consistent under a variety of experimental conditions. The distinctive yellow colour of a diffusion flames engulfs a coating during a test. Due to this, the process of intumescence has not been observed visually. Thermal imaging was used in this study because it allowed the user to bypass the flame and observe intumescence as it occurred. Using thermal imaging, the physical aspects of intumescence were studied in extensive detail and salient characteristics were identified. The appearance of surface pustules followed by majority of the expansion were characterised as the two distinct phases in the intumescence process. Analysis of the surface temperature revealed that the thermal profile of the surface was non-uniform and highly localized in nature. This was attributed to the higher temperature of the pustules relative to the paint surface. Results from thermal imaging combined well with the Schlieren technique to develop a coherent understanding of the expansion process. Diagnostic equipment, particularly thermal and digital imaging, were also used on tests conducted in a cone calorimeter. The results between cone heater and impinging flame-based tests were compared. The degree of intumescence, surface temperature profile and various characteristics were found to be different between both methods. Finally, the use of the techniques was extended to study the process of intumescence and complex char growth patterns on T-shaped panels coated with intumescent formulations. Char growth was observed to be complex and non-linear as compared to flat panel systems. A novel Image processing algorithm using the thermal imaging data from the cone calorimeter was developed marking a further advancement to the use of this technique and gain insight into the growth mechanism when examining a complicated three dimensional system such T-panels.
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Fry, Zachary S. "A LABORATORY SCALE STUDY OF INTUMESCENT COATINGS FOR PROTECTION OF BUILDING STRUCTURE MEMBERS FROM FIRES." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1402055149.
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Le, Bras Michel. "Etude du processus retardateur de flamme induit par la carbonisation ablative de matériaux polymères : application aux matériaux intumescents." Lille 1, 1997. http://www.theses.fr/1997LIL10097.
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La formulation d'un nouveau matériau polymère dont l'inflammation est retardée par un processus de carbonisation superficielle de type ablatif, en particulier l'intumescence, est étudiée en considérant la protection et l'intérêt économique du matériau. La première partie (tome 1) concerne des matériaux modèles. La caractérisation des carbones protecteurs nécessite des techniques analytiques utilisées classiquement avec les charbons fossiles (XRD, diffusion Raman et XPS), les polymères (RMN du #1#3c et du #1h des solides, RPE, absorption IR) et les phosphates (RMN du #3#1p des solides). Le revêtement carbone intumescent est un système catalytique : espèces acides minérales supportées par une charpente carbonée (polyaromatiques pontes par des motifs polymères). L'exploitation des données cinétiques, obtenues dans les conditions quasi-réelles d'un incendie, valide un modèle unidirectionnel de dégradation qui explique les performances des matériaux en terme de flux de chaleur. Dans la seconde partie (tome 2), la performance retard de flamme (fr) d'une formulation thermoplastique intumescente ou carbonisante est expliquée par le comportement antagoniste ou en synergie des adjuvants associés et la composition de la matrice polymère<br>Les caractéristiques chimiques (acidité, teneur en radicaux libres) ou physico-chimiques (organisation de la phase amorphe, structure du carbone, présence d'espèces cristallisées) expliquent la performance fr. L'intérêt de l'association d'adjuvants phosphates ou borates à des agents dérivés de la silice et d'une fonctionalisation du polymère est prouvé. Des associations de polymères, qui comprennent au moins une résine apte à la carbonisation et qui évitent le phénomène de rejet (exsudation) des adjuvants, se substituent aux agents de carbonisation classiques (polyols) avec des performances fr comparables. Ces nouveaux matériaux intumescents, de coûts égaux voire inférieurs à ceux actuellement utilisés, sont en cours de développement industriel
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Alistiqsa, Fathia. "Mise au point et étude de nouvelles formulations intumescentes polyphosphates d'ammonium - pentaerythritol : Application à l'ignifugation du polypropylène." Lille 1, 1993. http://www.theses.fr/1993LIL10050.
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Schmidt-Le, Tallec Yannick. "Valorisation de différents polyols dans des systèmes retardants de flamme : application au polyéthylène." Lille 1, 1992. http://www.theses.fr/1992LIL10129.
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L'objectif de ce travail concerne la valorisation de polyalcools dans des formulations retard au feu (RF) intumescentes. Ces formulations comportent : un polymère, un agent déshydratant qui catalyse la réaction de carbonisation (un phosphate d'ammonium), et un agent de carbonisation (un polyalcool). L'évaluation des propriétés RF des formulations (Polymère/Phosphate/Polyalcool) est menée: pour deux thermoplastiques (PE, PP); deux phosphates d'ammonium (PPA: Polyphosphate d'ammonium, PY: Pyrophosphate diammonique) et onze polyols. Elle permet de montrer l'importance de l'adaptation de la matrice polymère au système d'additifs ; le PY conduit à des propriétés RF supérieures au PPA; et l'influence des caractéristiques physico-chimiques des polyols. Une étude comparative de quatre formulations est réalisée en deux étapes : les études thermique et spectroscopique des systèmes d'additifs PY-Polyol montrent que l'intumescence se développe par formation d'espèces phosphocarbonées à basse température, les performances RF peuvent être reliées à la nature des espèces phosphocarbonées formées en fonction de la température de traitement thermique et également leur état d'organisation. La présence d'embryons de mésophase est mise en évidence pour les systèmes d'additifs présentant des propriétés RF satisfaisantes. L'analyse thermique (au calorimètre à cône) des formulations dans le PE et l'étude des profils de température prouve le maintien d'une température constante au sein du polymère. La durée de ce palier peut être corrélée aux propriétés RF des formulations. Le caractère de bouclier thermique du revêtement intumescent a donc pu être démontré. Certaines formulations permettent la conservation d'une partie du polymère (ou de ces produits de dégradation) après traitement dans les conditions du feu
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Drevelle, Christophe Delobel René Duquesne Sophie Le Bras Michel. "Étude de la dégradation de films à base de résine acrylique utilisée dans l'industrie textile." [S.l.] : [s.n.], 2002. http://www.univ-lille1.fr/bustl-grisemine/pdf/memoires/F2002-153.pdf.
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Mémoire de DEA : Chimie : Lille 1 : 2002.<br>Sur la p. de titre : DEA-Structure et dynamique des systèmes réactifs, PERF-Procédés d'élaboration de revêtements fonctionnels. Bibliogr. f. : 21-22. Annexes.
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Bahrani, Babak. "Effects of weathering on performance of intumescent coatings for structure fire protection in the wildland-urban interface." Thesis, The University of North Carolina at Charlotte, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1606131.
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<p> The objective of this study was to investigate the effects of weathering on the performance of intumescent fire-retardant coatings on wooden products. The weathering effects included primary (solar irradiation, moisture, and temperature) and secondary (environmental contaminants) parameters at various time intervals.</p><p> Wildland urban interface (WUI) fires have been an increasing threat to lives and properties. Existing solutions to mitigate the damages caused by WUI fires include protecting the structures from ignition and minimizing the fire spread from one structure to another. These solutions can be divided into two general categories: active fire protection systems and passive fire protection systems. Passive systems are either using pre-applied wetting agents (water, gel, or foam) or adding an extra layer (composite wraps or coatings). Fire-retardant coating treatment methods can be divided into impregnated (penetrant) and intumescent categories. Intumescent coatings are easy to apply, economical, and have a better appearance in comparison to other passive fire protection methods, and are the main focus of this study.</p><p> There have been limited studies conducted on the application of intumescent coatings on wooden structures and their performance after long-term weathering exposure. The main concerns of weathering effects are: 1) the reduction of ignition resistance of the coating layer after weathering; and 2) the fire properties of coatings after weathering since coatings might contribute as a combustible fuel and assist the fire growth after ignition.</p><p> Three intumescent coatings were selected and exposed to natural weathering conditions in three different time intervals. Two types of tests were performed on the specimens: a combustibility test consisted of a bench-scale performance evaluation using a Cone Calorimeter, and a thermal decomposition test using Simultaneous Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) method (also known as SDT). For each coating type and weathering period, three different radiative heat flux levels were used in the combustibility tests. Data obtained from the tests, including flammability and thermal properties, were gathered, analyzed, and compared to non-weathered specimens.</p><p> The results revealed visible effects of weathering on pre (and up to)-ignition flammability and intumescent properties, especially decreases in Time-to-Ignition (TTI), Time-to-Intumescence (t<sub>intu.</sub>), and (maximum) Intumescence Height (H<sub>intu.</sub>) values in weathered specimens. These results showed that the ignition resistance of the coating layers decreased after weathering exposure. On the other hand, the obtained results from weathered specimens for the post-ignition flammability properties, especially Peak Heat Release Rate (PHRR) and Effective Heat of Combustion (EHC) did not show a significant difference in comparison to the non-weathered samples. These results demonstrated that the weathered coating layer would not likely to act as an additional combustible fuel to increase fire spread.</p>
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Gardelle, Bastien. "Development and resistance to fire of intumescent silicone based coating : fire protection of steel in simulated fire." Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10079/document.
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L'objectif de ce travail de thèse est de développer des revêtements intumescents à base de résines de silicone pour la protection de l'acier en cas d’incendie. Les revêtements intumescents ont pour fonction d'assurer l'intégrité des structures en acier exposées au feu, ce métal perdant une grande partie de ses propriétés mécaniques au-dessus de 550°C. Les revêtements intumescents classiquement utilisés sont formulés à partir de résines organiques ce qui conduit à certaines limitations. Dans ce travail, des revêtements intumescents hybrides organiques-inorganiques à base de résines de silicone ont donc été développés. Dans un premier temps, il est montré que les résines silicones de types RTV (room temperature vulcanized) présentent les meilleures propriétés de barrière thermique. Par la suite, du graphite expansible a été incorporé en tant qu’agent gonflant à la résine silicone, pour permettre l'expansion du revêtement à haute température. Grâce à des interactions spécifiques entre le silicone et le graphite expansé, le revêtement obtenu présente d'excellentes propriétés de protection thermique. Ces résultats ont été attribués à ses propriétés de gonflement, à sa faible conductivité thermique à haute température et à la bonne cohésion du char développé. Des charges minérales supplémentaires ont ensuite été incorporées dans la formulation afin d'augmenter les propriétés mécaniques du char. Enfin, les paramètres essentiels régissant les propriétés de barrières thermiques des revêtements siliconés ont été mises en évidence. En jouant sur ces paramètres, il est possible de formuler des revêtements performants pour la protection de l'acier au cours d'un incendie<br>The purpose of this Ph.D work is to develop intumescent coatings for the protection of steel against fire. The aim of this coating is to ensure the integrity of steel structure exposed to fire since steel loses more than 50% of its load capacity above 550°C. Intumescent coatings expand in case of fire leading to the formation of an insulative barrier limiting the heat transfer from the heat source to the substrate. Most of these coatings are organic based and thus exhibit some limitations. Thus, in this work, hybrid organic-inorganic coatings based on silicone resins were developed. In a first step, it is shown that room temperature vulcanized silicone rubber is the silicone matrix exhibiting the best insulative properties in fire scenarios. Expandable graphite is then used as blowing agent to make the silicone swell when exposed to fire. Due to several interactions between silicone and expandable graphite at high temperature, the coating exhibits excellent fire performance. This performance was attributed to the swelling properties, the low thermal conductivity at high temperature and the good cohesion of the developed char. Additional fillers such as calcium carbonate and organoclay are incorporated in the formulation to increase the mechanical properties of the char. Finally, the critical parameters governing the insulative properties of intumescent silicone coatings have been determined. Moreover, it was pointed out that it is possible to develop silicone coatings exhibiting better fire performance than commercial intumescent paint for the protection of steel against fire in both hydrocarbon and cellulosic fire scenarios
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Gardelle, Bastien. "Development and resistance to fire of intumescent silicone based coating : fire protection of steel in simulated fire." Electronic Thesis or Diss., Lille 1, 2013. http://www.theses.fr/2013LIL10079.
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L'objectif de ce travail de thèse est de développer des revêtements intumescents à base de résines de silicone pour la protection de l'acier en cas d’incendie. Les revêtements intumescents ont pour fonction d'assurer l'intégrité des structures en acier exposées au feu, ce métal perdant une grande partie de ses propriétés mécaniques au-dessus de 550°C. Les revêtements intumescents classiquement utilisés sont formulés à partir de résines organiques ce qui conduit à certaines limitations. Dans ce travail, des revêtements intumescents hybrides organiques-inorganiques à base de résines de silicone ont donc été développés. Dans un premier temps, il est montré que les résines silicones de types RTV (room temperature vulcanized) présentent les meilleures propriétés de barrière thermique. Par la suite, du graphite expansible a été incorporé en tant qu’agent gonflant à la résine silicone, pour permettre l'expansion du revêtement à haute température. Grâce à des interactions spécifiques entre le silicone et le graphite expansé, le revêtement obtenu présente d'excellentes propriétés de protection thermique. Ces résultats ont été attribués à ses propriétés de gonflement, à sa faible conductivité thermique à haute température et à la bonne cohésion du char développé. Des charges minérales supplémentaires ont ensuite été incorporées dans la formulation afin d'augmenter les propriétés mécaniques du char. Enfin, les paramètres essentiels régissant les propriétés de barrières thermiques des revêtements siliconés ont été mises en évidence. En jouant sur ces paramètres, il est possible de formuler des revêtements performants pour la protection de l'acier au cours d'un incendie<br>The purpose of this Ph.D work is to develop intumescent coatings for the protection of steel against fire. The aim of this coating is to ensure the integrity of steel structure exposed to fire since steel loses more than 50% of its load capacity above 550°C. Intumescent coatings expand in case of fire leading to the formation of an insulative barrier limiting the heat transfer from the heat source to the substrate. Most of these coatings are organic based and thus exhibit some limitations. Thus, in this work, hybrid organic-inorganic coatings based on silicone resins were developed. In a first step, it is shown that room temperature vulcanized silicone rubber is the silicone matrix exhibiting the best insulative properties in fire scenarios. Expandable graphite is then used as blowing agent to make the silicone swell when exposed to fire. Due to several interactions between silicone and expandable graphite at high temperature, the coating exhibits excellent fire performance. This performance was attributed to the swelling properties, the low thermal conductivity at high temperature and the good cohesion of the developed char. Additional fillers such as calcium carbonate and organoclay are incorporated in the formulation to increase the mechanical properties of the char. Finally, the critical parameters governing the insulative properties of intumescent silicone coatings have been determined. Moreover, it was pointed out that it is possible to develop silicone coatings exhibiting better fire performance than commercial intumescent paint for the protection of steel against fire in both hydrocarbon and cellulosic fire scenarios
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Duquesne, Sophie. "Etude des procédés d'ignifugation de substrats polymères par revêtements intumescents : application aux polyuréthanes." Lille 1, 2001. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2001/50376-2001-Duquesne.pdf.
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Cette étude s'intéresse aux procédés d'ignifugation de substrats polymères par application de revêtements intumescents. Elle porte plus particulièrement sur l'ignifugation d'une mousse rigide de polyuréthane (PU) obtenue par application d'un revêtement constitué d'un liant PU et d'un additif "retard au feu" (RF). L'évaluation des propriétés RF de la mousse revêtue prouve l'intérêt de l'ajout de polyphosphate d'ammonium (APP) ou de graphite expansible (EG) dans le revêtement. Une approche de la toxicité des effluents gazeux émis sous différentes conditions de dégradation montre une réduction de l'émission de gaz toxiques (en particulier CO et HCN) dans le cas des revêtements ignifugés. L'étude du mécanisme de la dégradation et de la carbonisation des différents revêtements permet de mieux comprendre le mode de protection au feu des deux additifs étudiés. Pour le système PU/APP, des interactions additif / polymère conduisant à la formation d'un résidu stable à haute température sont mises en évidence. Ce phénomène n'est pas observé pour la formulation PU/EG. Une approche chimique du processus de carbonisation des revêtements PU, PU/APP et PU/EG montre qu'en présence d'APP, une structure phosphocarbonée stable se forme et que le processus de carbonisation inclut des mécanismes radicalaires<br>Concernant le système PU/EG, une faible modification du processus de carbonisation naturelle du PU est observée. La caractérisation du processus de carbonisation, menée selon une approche physique met en évidence une aptitude à la déformation de la structure carbonée formée par dégradation du revêtement PU/APP. Aucours d'un incendie, cette structure va donc se déformer plutôt que de se fissurer et ainsi permettre un maintien des performances RF. Dans le cas du système PU/EG, l'épaisseur importante, la faible densité et, comme il est possible de le supposer la faible conductivité thermique du bouclier intumescent permettent de comprendre le mode d'action de l'EG
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Didane, Nizar. "Elaboration et caractérisation fonctionnelle de matériaux polymères intumescents : application aux textiles de recouvrement." Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10062/document.
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Ce travail se place dans le contexte de développement de nouveaux textiles ignifugés dédiés au recouvrement de sièges pour le secteur ferroviaire. Il porte plus particulièrement sur l’amélioration des propriétés au feu du poly (éthylène téréphtalate) (PET) par addition en voie fondue de retardateurs de flammes. Un mélange synergique d’additifs basé sur la littérature a été sélectionné (phosphinates de zinc et nanocharges OctaMethyl POSS) et a permis l’élaboration de multifilaments en PET ignifugé avec une teneur en additifs d’environ 10 % en masse. D’autres systèmes ignifugés à base de phosphinates de zinc ou d’aluminium et différents POSS ont été également étudiés. Les matériaux élaborés ont montré des comportements au feu distincts qui semblent liés d’une part à la dégradation thermique des nanocharges et les composés qu’ils libèrent et d’autre part aux réactions entre les POSS et le métal présent dans les additifs phosphorés. L’élaboration de multifilaments à taux de charges élevés (20 % en masse) a été étudiée avec des phosphinates de zinc ou d’aluminium qui sont respectivement fusibles et infusibles. Les modifications du comportement rhéologique du PET en présence des additifs ont étaient diminuées par l’incorporation du poly (butylène téréphtalate) (PBT). Des travaux sur l’ignifugation des textiles par mélange de fibres ou par enduction ont été menés et ont conduit à des résultats intéressants et complémentaires à l’étude par voie de filage. Les aspects de compatibilité et d’état de dispersion entre additifs et polymère et leur impact sur les propriétés physiques des matériaux fibreux ont été également étudiés<br>This work is dealing with the development of fire resistant covering textiles for railway field. It particularly concerns the improvement of poly (ethylene terephthalate) (PET) fire properties by melt blending fire retardants. Based on literature, a synergistic blend of additives has been selected (zinc phosphinates and OctaMethyl POSS nanofillers) and processed into PET multifilaments with 10% of loading content. Other fire resistant systems combining zinc or aluminium phosphinates with different POSS has been also studied. The developed materials showed distinct fire behaviours which could be related in one hand, to the released species of POSS through thermal degradation and on the other hand, to reactions between POSS and the metal element on the phosphorus-containing agent. The elaboration of highly loaded multifilaments (20 wt.%) has been studied with zinc or aluminium phosphinates which are respectively fusible and infusible. Rheological modifications occurred when fillers are added to PET and incorporation of poly (butylene terephthalate) (PBT) diminished the observed phenomena. Works on textile fire retardancy by fibres blending or back coating has been led and gave interesting results. Compatibility and dispersion state of fillers on polymer and their impact on the fibrous materials physical properties has been also studied
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Duquesne, Sophie Delobel René. "Etude des procédés d'ignifugation de substrats polymères par revêtements intumescents application aux polyuréthanes /." Villeneuve d'Ascq : Université des sciences et technologies de Lille, 2007. https://iris.univ-lille1.fr/dspace/handle/1908/971.
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Reproduction de : Thèse de doctorat : Spectrochimie, molécules, solides, réactivité : Lille 1 : 2001.<br>Label européen. Résumé en français et en anglais. Titre provenant de la page de titre du document numérisé. Bibliogr. en fin de chapitres.
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Giraud, Stéphane Bourbigot Serge Tighzert Lan. "Microencapsulation d'un diisocyanate et d'un phosphate d'ammonium." [S.l.] : [s.n.], 2002. http://www.univ-lille1.fr/bustl-grisemine/pdf/extheses/50376-2002-311-312.pdf.
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Schuerbeck, Cortés Felipe Edgardo Van. "Modelación por elementos finitos de pintura intumescente aplicada sobre perfiles de acero expuestos a incendio." Tesis, Universidad de Chile, 2013. http://repositorio.uchile.cl/handle/2250/114061.
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Ingeniero Civil<br>El objetivo del presente trabajo fue buscar una herramienta computacional eficaz y rápida, para estudiar el comportamiento frente a la acción del fuego de los elementos estructurales de acero protegidos con pintura intumescente.
En la búsqueda de esta herramienta de trabajo se desarrollaron tres modelaciones numéricas y/o computacionales que simulan el desarrollo de transferencia de calor dinámica que se genera en el ensayo normalizado de resistencia al fuego definido en la norma NCh 935/1 Of 1997.
Para su desarrollo se utilizó como base de calibración una serie de ensayos de resistencia al fuego de pilares de acero protegidos con pintura intumescente, los cuales que se realizaron en el Laboratorio de Incendios del IDIEM de la Universidad de Chile, según lo indicado en la norma NCh 935/1. Para efecto del estudio se consideró la relación tiempo-temperatura de cada elemento ensayado.
El primer modelo se desarrolló a partir de una serie de regresiones numéricas sobre la información obtenida de los ensayos realizados y permite predecir la temperatura promedio de un perfil de acero expuesto al fuego como una función del tiempo de exposición al fuego, de su masividad y espesor inicial de la pintura intumescente.
El segundo modelo tiene como base la fórmula 4.22 del Eurocódigo 3 Parte 1.2, del año 2001, que permite determinar el aumento de la temperatura de la sección transversal de un perfil de acero protegido del fuego con diversos materiales tales como: placas de yeso-cartón, madera, morteros livianos y otros. Esta fórmula no considera la pintura intumescente dentro de las soluciones de protección, por lo que para esta modelación se estudió la forma de incluirla y validar el método.
El tercer modelo utiliza un software de elementos finitos llamado COMSOL Multiphysics versión 4.0, Módulo de Transferencia de Calor. Este software simula el comportamiento térmico dinámico considerando la transmisión térmica por conducción, convección y radiación, para determinar las variaciones de temperatura de un perfil de acero protegido con pintura intumescente expuesto a las condiciones de un incendio.
Como resultado de este estudio, puede afirmarse que las tres modelaciones numéricas cumplen el objetivo propuesto, dado que permiten reproducir analíticamente y en corto tiempo el comportamiento al fuego por conducción térmica dinámica de los elementos de acero cuando se protegen con pintura intumescente. Los resultados son similares a los obtenidos en ensayos de resistencia al fuego realizados de acuerdo con la norma NCh 935/1 Of 1997.
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Rush, David Ian. "Fire performance of unprotected and protected concrete filled steel hollow structural sections." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8298.
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Concrete filled steel hollow structural (CFS) sections are increasingly used to support large compressive loads in buildings, with the concrete infill and the steel tube working together to yield several benefits both at ambient temperature and during a fire. These members are now widely applied in the design of highly optimized multi-storey and high rise buildings where fire resistance ratings of two or more hours may be required. Whilst the response and design of these sections at ambient temperatures is reasonably well understood, their response in fire, and thus their fire resistance design, is less well established. Structural fire resistance design guidance is available but has been developed based on tests of predominantly short, concentrically-loaded, small-diameter columns in braced frames using normal strength concrete. The current prescriptive guidance is limited and the design of CFS columns is thus often based on a detailed performance based approach, which can be time consuming and expensive and which is generally not well supported by a deep understanding of CFS columns’ behaviour in real fires. This thesis aims to understand the fundamental thermal and mechanical factors at play within these sections so as to provide guidance on how to improve their design for fire resistance when applied either as unprotected or protected sections. A meta-analysis of available furnace test data is used to demonstrate that current guidance fails to capture the relevant mechanics and thus poorly predicts fire resistance. It is also demonstrated that the predictive abilities of the available design standards vary with physical characteristics of the CFS section such as shape and size. A factor which has been observed in furnace tests on CFS sections but which is not accounted for in available guidance is the formation of an air gap between the steel tube and the concrete core due to differential expansion; this affects their structural response in fire. The insulating effect of air gap formation has not previously been addressed in literature and an experimental program is presented to systematically assess the effects of a gap on the heat transfer through the section; showing that the presence of even a 1 mm gap is important. To explicitly assess the heat transfer response within both unprotected and fire protected (i.e. insulated) CFS sections, 34 large scale standard furnace tests were performed in partnership with an industry sponsor. Fourteen tests on large scale unloaded unprotected CFS sections are presented to assess current capability to predict the thermal response and to assess the effects of different sectional and material parameters on heating. New best practice thermal modelling guidance is suggested based on comparison between the models and observed temperatures from the tests. Twenty CFS specimens of varying size and shape, protected with different types and thicknesses of intumescent paint fire insulation, were also tested unloaded in a furnace to understand the thermal evolution within protected CFS sections and to develop design guidance to support application of intumescent coatings in performance based fire resistance design of CFS sections. These tests demonstrate that the intumescent coatings were far more effective than expected when applied to CFS sections, and that current methods of designing the coatings’ thickness are overly conservative. The reason for this appears to be that the calculation of effective section factor which is used in the prescription of intumescent coating thicknesses is based on the thermal response of unprotected CFS sections which display fundamentally different heating characteristics from protected sections due to the development of a thermal gradient in the concrete core. It is also demonstrated (by calculation supported by the testing presented herein) that the steel failure temperature (i.e. limiting temperature) of an unprotected CFS column in fire is significantly higher than one which is protected; procedures to determine the limiting temperature of protected sections are suggested. Finally, the residual strength of fire-exposed CFS columns is examined through structural testing of 19 of the 34 fire tested columns along with unheated control specimens. The results provide insights into the residual response of unprotected and protected CFS section exposed to fire, and demonstrate a reasonable ability to calculate their residual structural capacity. The work presented in this thesis has shed light on the ability of available guidance to rationally predict the thermal and structural response to fire of CFS columns, has improved the understanding of the thermal evolution within protected and unprotected CFS sections in fire, has provided best-practice guidance and material input parameters for both thermal and structural modelling of CFS sections, and has improved understanding of the residual capacity of CFS sections after a fire.
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Souza, Cassiara Camelo Eloi de. "Qualidade, perfil eletroforético e de voláteis, fitoquímicos bioativos e atividade antioxidante de frutos de genótipos de macaibeira (acrocomia intumescens drude)." Universidade Federal da Paraíba, 2016. http://tede.biblioteca.ufpb.br:8080/handle/tede/9424.
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Previous issue date: 2016-02-26<br>The objective of this research was to evaluate the fruit quality of seven native genotypes macaw Atlantic Forest and environment, through physical, chemical, antioxidant capacity, fatty acid profile (GC-FID), Phenolic (HPLC-UV) and volatile (SPME-GC-MS) in order to obtain data on potential use and variability of this species. The pulp and almond can be considered as an important source of carbohydrates, lipids, minerals and K, Fe, Ca and P. Almonds are rich in globulin and do not have trypsin inhibitors and/or haemagglutinating activity. The pulp showed high levels of UFA (89.81%) being more abundant oleic acid (8.09 g.100g-1), linoleic (1.56 g.100g-1) and palmitic acid as well as excellent nutritional quality index. Almond also rich in oleic acid (7.61 g.100g-1) contains significant levels of AGS (14.35 g.100g-1), especially lauric, myristic and palmitic acid. The oils have good thermal stability up to 230 °C with DTA curves of exothermic character. The pulp has very high levels of carotenoids (8.64 mg.100g-1) and can be considered rich in vitamin C (47,60 mg.100g-1). The highest concentrations of total phenolics were observed in the peel (274.55 mg.100g-1) and almond (147.23 mg.100g-1). The strongest positive and significant correlation occurred between ABTS● + and PET. Phenolic acids and flavonols were the main components in the studied fractions. The phenolic catechin was only found in all samples. However, the phenolic myricetin was identified with the highest concentration. Genotype 6 stood out to contain the highest concentrations of carotenoids, yellow flavonoids and PET in the peel, ascorbic acid and yellow flavonoids in the pulp and antioxidant activity in the peel. Genotype 7 has the highest content of carotenoids and PET in the pulp. Through the HS-SPME-GC-MS system was first identified (62) Volatile compounds in the pulp. Terpenes, aldehydes and alcohols were the main. The alcohol content ranged from 1.5 to 44.99%; the dioxalanes were present in all genotypes; the hexanal was the main representative of the aldehydes. The pulp macaw has a strong and exotic aroma and high levels of β-Cis-Ocimene, β-Trans-Ocimene and Allo-aromadendrene. The PCA was efficient to indicate the most significant features in the differentiation between the genotypes that showed genetic variability. This fruit can therefore contribute substantially to the supply of nutrients, dietary enrichment of bioactive source and adding value to natural resources in the Brazilian Atlantic Forest for its fresh or processed consumption.<br>objetivo desta pesquisa foi avaliar a qualidade de frutos de sete genótipos de macaibeira nativos da Mata Atlântica e entorno, por meio da caracterização física, química, capacidade antioxidante, perfil de ácidos graxos (GC-FID), fenólicos (HPLC-UV) e voláteis (SPME-GC-MS) com vistas a obter dados sobre potencial de utilização e variabilidade desta espécie. A polpa e amêndoa podem ser consideradas como importante fonte de carboidratos, lipídios, minerais e K, Fe, P e Ca. As amêndoas são ricas em globulinas e não possuem inibidores de tripsina e/ou atividade hemaglutinante. A polpa apresentou elevados teores de AGI (89,81%) sendo mais abundantes os ácidos oleico (8,09 g.100g-1), linoleico (1,56 g.100g-1) e palmítico além de excelentes índices de qualidade nutricional. A amêndoa, também rica em ácido oleico (7,61 g.100g-1) contem teores significativos de AGS (14,35 g.100g-1), sobretudo láurico, mirístico e palmítico. Os óleos possuem boa estabilidade térmica até 230 ºC com curvas de DTA de caráter exotérmico. A polpa possui teores muito elevados de carotenoides totais (8,64 mg.100g-1) e pode ser considerada rica em vitamina C (47,60 mg.100g-1). As maiores concentrações de fenólicos totais foram observados na casca (274,55 mg.100g-1) e na amêndoa (147,23 mg.100g-1). A correlação significativa e positiva mais forte ocorreu entre ABTS●+ e PET. Os ácidos fenólicos e flavonóis foram os compostos majoritários nas frações pesquisadas. A catequina foi o único fenólico encontrado em todas as amostras. No entanto, a miricetina foi o fenólico identificado com a maior concentração. O genótipo 6 destacou-se por conter as maiores concentrações de carotenoides totais, flavonoides amarelos e PET na casca, ácido ascórbico e flavonoides amarelos na polpa e maior atividade antioxidante na casca. O genótipo 7 tem o maior teor de carotenoides totais e PET na polpa. Através do sistema HS-SPME-GC-MS foram identificados pela primeira vez (62) compostos voláteis na polpa. Terpenos, aldeídos e álcoois foram os principais. O teor de álcoois oscilou de 1,5 a 44,99%; os dioxalanes estiveram presentes em todos os genótipos; o hexanal foi o principal representante dos aldeídos. A polpa de macaíba apresenta aroma forte e exótico e elevados teores de β-Cis-Ocimene, β-Trans-Ocimene e Allo-aromadendrene. A ACP se mostrou eficiente para indicar as características mais significativas na diferenciação entre os genótipos que apresentaram variabilidade genética. Este fruto, portanto, pode contribuir substancialmente para o fornecimento de nutrientes, enriquecimento da dieta, fonte de bioativos e agregação de valor aos recursos naturais da Mata Atlântica brasileira pelo seu consumo fresco ou processado.
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Dabrowski, François. "Optimisation et compréhension de procédés d'ignifugation de polymères techniques." Lille 1, 2001. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2001/50376-2001-185-186.pdf.
Full textAbstract:
Ce travail porte sur les procédés d'ignifugation du polyamide-6,6 (PA), un polymère technique utilisé pour l'application électrique. Le pyrophosphate et le polyphosphate de mélamine sont deux additifs intumescents dont l'incorporation, dans le PA, vierge ou renforcé par des fibres de verre, permet l'obtention de propriétés retard au feu (FR) et la satisfaction d'un cahier des charges industriel. De plus, la présence du renfort minéral induit des modifications des performances feu. L'étude est donc orientée sur la compréhension des influences des additifs FR et des fibres de verre sur les propriétés feu des formulations. Les stabilités thermiques sous air des matériaux sont évaluées, pour comprendre le mode de protection feu. L'existence d'interactions entre la matrice polymère et les additifs sont mises en évidence. Elles entraînent, entre autres, la formation d'un résidu stable aux températures élevées. Par ailleurs, des interactions entre le renfort minéral et les systèmes FR sont également observées. La modélisation cinétique des processus de dégradation des différents systèmes, en utilisant la méthode des paramètres cinétiques invariants, permet la compréhension des influences des adjuvants et des fibres sur les mécanismes de dégradation des matériaux. L'étude des effluents de dégradation des matériaux, sous différentes conditions, permet de caractériser les effets des additifs et des fibres de verre sur la composition de la phase gaz. Une contribution de cette dernière à la protection feu du matériau peut être supposée. Enfin, une approche chimique de la dégradation des matériaux permet de proposer un mécanisme de protection feu au sein de la phase condensée, via la formation d'une couche intumescente contenant une structure phosphocarbonée stable. Finalement, il est montré que la charge de renfort modifie la chimie de dégradation des systèmes FR.
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Dabrowski, François Delobel René. "Optimisation et compréhension de procédés d'ignifugation de polymères techniques." [S.l.] : [s.n.], 2001. http://www.univ-lille1.fr/bustl-grisemine/pdf/extheses/50376-2001-185-186.pdf.
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Roque, Sérgio. "Estudo experimental do comportamento de elementos em aço protegidos com tinta intumescente em condições de incêndio." Master's thesis, Instituto Politécnico de Bragança, Escola Superior de Tecnologia e Gestão, 2011. http://hdl.handle.net/10198/4352.
Full textAbstract:
Este relatório apresenta o trabalho desenvolvido no âmbito de uma tese de
mestrado em Engenharia da Construção, incluído num projecto de investigação
PTDC/EME-PME/64913/2006, apoiado pela Fundação para a Ciência e a
Tecnologia.
A motivação desta investigação experimental está relacionada com a
necessidade de definir e conhecer o comportamento da protecção passiva de tinta
intumescente, de elementos e estruturas metálicas, definir um método
simplificado de cálculo para protecções reactivas e ainda produzir dados
essenciais para a calibração e ou validação de novos métodos simplificados e
avançados de cálculo.
Foram previstas quatro séries de testes, com 52 ensaios em perfis metálicos
de diferentes secções (IPE, SHS, CHS e LNP). A cada secção correspondeu uma
série de 13 ensaios. Em cada série foram realizados 2 ensaios à temperatura
ambiente (acção mecânica incremental) e 11 ensaios de resistência ao fogo, com
diferentes valores de protecção e níveis de carga
A aplicação de tinta intumescente permitiu com que todos os elementos
atingissem a sua ruptura num período de tempo superior, aumentando assim a sua capacidade de resistência ao fogo. Nos elementos de secção IPE e CHS
observou-se que quanto maior a camada de protecção, maior a resistência do
elemento. O mesmo não se verificou nos elementos de secção SHS, devido ao
fenómeno de retracção verificado para espessuras de protecção superior. O
fenómeno de retracção verificou-se ainda na maioria dos elementos com secção
CHS. This report presents the work undertaken as part of a master's thesis in
Construction Engineering, included in a research project PTDC/EMEPME/
64913/2006, supported by the Portuguese Foundation for Science and
Technology.
The motivation for this experimental research is to define and understand the
behaviour of passive protection of intumescent paint, applied to steel structures
and elements, define a simplified method for the design of reactive protections and
produce experimental data for calibration / validation of new simplified methods
and advanced calculation methods.
52 bending testes were planned with different steel cross-sections (IPE,
SHS, CHS and LNP) grouped in four series. 13 tests were prepared for each cross
section (series). In each series 2 tests were developed at room temperature
(incremental mechanical action) and 11 fire resistance tests were developed with
different level of protection and load.
The use of intumescent paint allowed higher fire resistance time for all tested
elements. The fire resistance of IPE e CHS section elements increased with the
level of the protection. A different behaviour was verified for the SHS due to the “pull-back” mechanism of the intumescent layer. This “pull-back” phenomenon
occurred for the most of CHS section elements.<br>info:eu-repo/grantAgreement/FCT/5876-PPCDTI/64913/PT
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Delaval, Damien. "Développement et caractérisation de systèmes intumescents retardateurs de flamme pour polypropylènes recyclés issus des véhicules usagés." Electronic Thesis or Diss., Lille 1, 2009. http://www.theses.fr/2009LIL10015.
Full textAbstract:
Un des objectifs de ces travaux a été d’évaluer l’effet du recyclage et de polluants (huile moteur (HM) et éthylène glycol (EG)) sur les propriétés d’usage de polypropylènes chocs issus de véhicules usagés. Le recyclage (ici limité à six cycles d’extrusion) n’entraîne pas de modification significative des propriétés mécaniques. L’étude de la cinétique de cristallisation des polymères pollués a montré que l’EG retarde la cristallisation du copolymère. La cinétique de dégradation a permis de simuler et de quantifier les différentes étapes de dégradation des matériaux. Le comportement au feu des polymères est par ailleurs amélioré de manière significative après recyclage et en présence des polluants, particulièrement dans le cas de la pollution à l’HM. Le deuxième axe de l’étude a été consacré à l’ignifugation des matériaux par des systèmes intumescents (formulation à base de polyphosphate d’ammonium (APP) avec et sans agent de synergie (borate de zinc (ZB))). Dans tous les cas les matériaux recyclés et pollués présentent des performances satisfaisantes. Nous avons montré que l’efficacité du char intumescent est gouvernée par sa vitesse de formation et par sa conductivité thermique qui sont influencées positivement par la pollution (avec APP/ZB) et le recyclage (avec APP) (augmentation de la vitesse et diminution de la conductivité thermique). La caractérisation chimique des structures qui se développent dans des conditions de combustion montre la formation d’une structure phosphocarbonée contenant des polyaromatiques, des pyrophosphates et de l’acide phosphorique ainsi que, dans le cas du ZB, des borophosphates (sa formation permet de renforcer la structure intumescente)<br>The impact of recycling and pollutants (engine oil (EO) and ethylene glycol (EG)) on the intrinsic properties of polypropylene-based materials coming from end-of-life cars was investigated. Recycling (limited here to six extrusion cycles) is not detrimental to the mechanical properties of the polymeric matrices. The crystallization kinetics study realized on the polluted polymers showed that the presence of EG delays crystallization. The degradation kinetics allowed to simulate and quantify the different degradation steps of the materials. Pollutants and recycling also lead to an improvement of the reaction to fire of our copolymer, especially in the case of EO-containing samples. The second part of the work was devoted to the study of the flame retardant properties of our materials provided by ammonium polyphosphate (APP) with or without zinc borate (ZB) (synergistic agent)). In all cases recycled and polluted materials show satisfying performances. It was found that the efficiency of the protective barrier provided by the char is governed by the rapidity of its formation and its thermal conductivity which are positively influenced by EO (with APP/ZB) and recycling (with APP) (increase of the formation rate and decrease of the conductivity). Chemical characterization of the structures formed in a fire scenario reveals the formation of a phosphocarboneous structure containing polyaromatics, pyrophosphates and phosphoric acid and when zinc borate is used, borophosphates which can reinforce the intumescent structure
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Delaval, Damien. "Développement et caractérisation de systèmes intumescents retardateurs de flamme pour polypropylènes recyclés issus des véhicules usagés." Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10015/document.
Full textAbstract:
Un des objectifs de ces travaux a été d’évaluer l’effet du recyclage et de polluants (huile moteur (HM) et éthylène glycol (EG)) sur les propriétés d’usage de polypropylènes chocs issus de véhicules usagés. Le recyclage (ici limité à six cycles d’extrusion) n’entraîne pas de modification significative des propriétés mécaniques. L’étude de la cinétique de cristallisation des polymères pollués a montré que l’EG retarde la cristallisation du copolymère. La cinétique de dégradation a permis de simuler et de quantifier les différentes étapes de dégradation des matériaux. Le comportement au feu des polymères est par ailleurs amélioré de manière significative après recyclage et en présence des polluants, particulièrement dans le cas de la pollution à l’HM. Le deuxième axe de l’étude a été consacré à l’ignifugation des matériaux par des systèmes intumescents (formulation à base de polyphosphate d’ammonium (APP) avec et sans agent de synergie (borate de zinc (ZB))). Dans tous les cas les matériaux recyclés et pollués présentent des performances satisfaisantes. Nous avons montré que l’efficacité du char intumescent est gouvernée par sa vitesse de formation et par sa conductivité thermique qui sont influencées positivement par la pollution (avec APP/ZB) et le recyclage (avec APP) (augmentation de la vitesse et diminution de la conductivité thermique). La caractérisation chimique des structures qui se développent dans des conditions de combustion montre la formation d’une structure phosphocarbonée contenant des polyaromatiques, des pyrophosphates et de l’acide phosphorique ainsi que, dans le cas du ZB, des borophosphates (sa formation permet de renforcer la structure intumescente)<br>The impact of recycling and pollutants (engine oil (EO) and ethylene glycol (EG)) on the intrinsic properties of polypropylene-based materials coming from end-of-life cars was investigated. Recycling (limited here to six extrusion cycles) is not detrimental to the mechanical properties of the polymeric matrices. The crystallization kinetics study realized on the polluted polymers showed that the presence of EG delays crystallization. The degradation kinetics allowed to simulate and quantify the different degradation steps of the materials. Pollutants and recycling also lead to an improvement of the reaction to fire of our copolymer, especially in the case of EO-containing samples. The second part of the work was devoted to the study of the flame retardant properties of our materials provided by ammonium polyphosphate (APP) with or without zinc borate (ZB) (synergistic agent)). In all cases recycled and polluted materials show satisfying performances. It was found that the efficiency of the protective barrier provided by the char is governed by the rapidity of its formation and its thermal conductivity which are positively influenced by EO (with APP/ZB) and recycling (with APP) (increase of the formation rate and decrease of the conductivity). Chemical characterization of the structures formed in a fire scenario reveals the formation of a phosphocarboneous structure containing polyaromatics, pyrophosphates and phosphoric acid and when zinc borate is used, borophosphates which can reinforce the intumescent structure
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Kruger, Hermanus Joachim. "Characterisation of expandable graphite and its flame retardant abilities in flame retardant systems for polyethylene." Thesis, University of Pretoria, 2017. http://hdl.handle.net/2263/61304.
Full textAbstract:
In the pursuit of lower cost intumescent flame retardant (IFR) systems, the compound expandable graphite (EG) was identified. This compound delivers high flame retardant performance but provides non-uniform thermal shielding when exposed to open flame from below due to negative gravitational effects. It was theorised that this may be remedied either through ion exchange of the interstratified ions with low glass transition ions or through use in binary systems with other compounds. Two classes of commercial EG were identified, namely a low and a high expansion onset temperature EG compound. Extensive characterisation of each EG compound was undertaken to assess its composition, expansion mechanisms and onset temperatures in order to identify compatible compounds for binary use. The susceptibility of each compound to ion exchange was also assessed. An industrial IFR ethylenediamine phosphate (EDAP) and a novel flame retardant were synthesised for assessment in binary use with EG. Coupled with the above study, this project developed two novel fire testing techniques as low cost alternatives to well-established fire testing methods such as cone calorimetry.
The first technique involved an open flame fire testing method which allowed vertical or horizontal testing. Digital and infrared (IR) video recording during operation facilitated comparison of multiple performance indicators further strengthening this method. The second technique allowed assessment of the mass loss resistance of each compound during laser pyrolysis. Characterisation of the EG compounds allowed development of structural models to describe each compound and explain the mechanisms of their expansion and gaseous release. Exhaustive ion exchange testing did not deliver favourable results, necessitating the pursuit of compounds for binary use with EG. A novel IFR was synthesised by neutralising 3,5-diaminobenzoic acid hydrochloride salt with ammonium dihydrogen phosphate. This compound, which melts at 257 °C, decomposes concurrently to release carbon dioxide gas which promotes intumescent charring. The flame retardant performance of this compound and EDAP as primary flame retardants and in combination with expandable graphite was evaluated. As a proof of concept, the novel compound was tested as a primary flame retardant using cone calorimetry after which its utility in binary systems with low temperature expandable graphite was tested. Substantial decreases in peak heat release rate (pHRR) and flame out time were achieved for all binary systems. This success led to testing of a number of combinations of low and high expansion onset EG and the other IFRs to identify the highest performing combination, which proved to be the 10-10 EDAP-EG system. Combinations of EG and the novel compound also showed excellent results. The novel fire testing techniques proved effective in identifying high performance combinations and showed comparable trends to those measured in cone calorimetry, at a greatly reduced cost and material requirement. IR analysis of open flame fire testing indicated increases in the temperatures required for ignition and burn through of the substrate. Observations, corroborated by optical video, showed that cohesive and uniform thermal shielding was achieved in all binary systems tested.
This study illustrates that systems of 10% EG combined with either 10% DABAP or 10% EDAP are both the most economical binary systems tested but are extremely high performance systems as well. Both of these systems delivered excellent results while being more economic than the widely used industrial system with a 25-30% EDAP loading. It is recommended that these compounds be considered for industrial use. Furthermore, the effective fire testing techniques developed in this study may be utilised in future fire testing to identify high performance compounds at a lower cost prior to further assessment through methods such as cone calorimetry.<br>Thesis (PhD)--University of Pretoria, 2017.<br>Chemical Engineering<br>PhD<br>Unrestricted
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Krishnamoorthy, Renga Rao. "The analysis of partial and damaged fire protection on structural steel at elevated temperature." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/the-analysis-of-partial-and-damaged-fire-protection-on-structural-steel-at-elevated-temperature(de0ddd3a-7256-439c-af53-68aeb521c5d9).html.
Full textAbstract:
Intumescent coating fire protection on steel structures is becoming widely popular in the UK and Europe. The current assessment for the fire protection performance method using the standard fire resistance tests is not accurate, owing to the reactive behaviour of intumescent coating at elevated temperature. Moreover, the available intumescent coating temperature assessment method provided in the Eurocode for structural steel at elevated temperature does not incorporate the steel beam's behaviour and/or assessment for partial protection and/or damaged protection. The research work presented provides additional information. on the assessment of partial and/or damaged intumescent coating at elevated temperature. In the scope of the investigation on the thermal conductivity of intumescent coating, it was found that the computed average thermal conductivity was marginally sensitive to the density and emissivity at elevated temperature. However, the thermal conductivity was found to be reasonably sensitive to the differences in initial dft's (dry film thicknesses). In this research, a numerical model was developed using ABAQUS to mimic actual indicative test scenarios to predict and establish the temperature distribution and the structural fire resistance of partial and/or damaged intumescent coating at elevated temperatures. Intumescent coating actively shields when the charring process occurs when the surface temperature reaches approximately 250°C to 350°C. Maximum deflection and deflection failure times for each damage scenario were analyzed by applying specified loading conditions. It was also found that the structural fire resistance failure mode of intumescent coating on protected steel beams was particularly sensitive to the applied boundary conditions. Careful selection of nodes in the element was necessary to avoid numerical instability and unexpected numerical error during analysis. An assessment of various numerical models subjected to a-standard fire with partially protected 1 mm intumescent coating was analysed using ABAQUS. An available unprotected test result was used as a benchmark. The outcome suggests that the fire resistances of the beams were found to be sensitive to the location of the partial and/or damage protection. The overall fire resistance behaviour of intumescent coating at elevated temperature was summarized in a 'typical deflection regression' curve. An extensive parametric analysis was performed on localized intumescent coating damage with various intumescent coating thicknesses between 0.5mm to 2.0mm. It was found that the average deflection was linear for the first 30 mins of exposure for all the variables, damage locations and intumescent thicknesses. It was concluded that a thicker layered intumescent coating may not be a better insulator or be compared to a much less thick intumescent coating at elevated temperature. The use of passive fire protection, however, does enhance the overall fire resistance of the steel beam, in contrast to a naked steel structure. The research work investigated the intumescent coating behaviour with different aspects of protection and damage and the outcome of the assessment provided a robust guide and additional understanding of the performance of intumescent coating at elevated temperature.
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Sales, Carlos Alexandre Santos. "Análise da resistência ao fogo de blocos de alvenaria cerâmica de vedação utilizando proteção de tinta intumescente." Universidade Católica de Pernambuco, 2016. http://www.unicap.br/tede//tde_busca/arquivo.php?codArquivo=1203.
Full textAbstract:
Os incêndios estão presentes na história de várias cidades do mundo e, em algumas delas, chegaram a protagonizar mudanças significativas no desenho urbano e nas características construtivas de suas edificações. No Brasil, o conhecimento sobre segurança contra incêndio em edificações só se tornou assunto de importância após duas grandes tragédias nacionais: os incêndios nos edifícios Andraus (em 1972, com dezesseis mortos) e Joelma (em 1974, com cento e oitenta e nove mortos), ambos na cidade de São Paulo. Atualmente, após a tragédia ocorrida na boate Kiss em Santa Maria - RS em 2013, que culminou com a morte de 242 jovens, muitas alterações nas legislações estaduais de proteção contra incêndio estão sendo sugeridas no Congresso Nacional e nas Assembleias Legislativas Estaduais, porém, em sua maioria, sem respaldo científico e normativo. Juntamente com as mudanças legislativas, muitos produtos e equipamentos surgem diariamente com o objetivo de proteger a vida humana e o patrimônio histórico e cultural. Nesse sentido, surgem as proteções passivas por tintas intumescentes que, conforme se verifica com os resultados desse trabalho, possuem a propriedade de manter o conforto e isolamento térmico adequados, além de manter a resistência a compressão e capacidade máxima de carga dos blocos cerâmicos de vedação em níveis aceitáveis pela norma brasileira, após a exposição direta a chama durante um período de 60 minutos.<br>Fires are present in the history of cities around the world, and some of them came to star in significant changes in urban design and the construction characteristics of their buildings. In Brazil, the knowledge Fire Safety in buildings only became a matter of importance after two great national tragedies: fires in Andraus buildings (in 1972, with sixteen dead) and Joelma (in 1974 with one hundred eighty-nine dead) both in São Paulo. Currently, after the tragedy at Kiss nightclub in Santa Maria - RS in 2013, which culminated in the death of 242 young people, many changes in state laws fire protection are being suggested in Congress and in State Legislative Assemblies, however, in mostly without scientific and regulatory support. Along with legislative changes, many products and equipment appear daily in order to protect human life and the historical and cultural heritage. In this sense, there are passive protections for intumescent coatings that, as evidenced by the results of this work, have the property to maintain comfort and thermal insulation appropriate, while maintaining resistance to compression and maximum load capacity of sealing ceramic blocks at acceptable levels by the Brazilian standard, after direct exposure to flame for a period of 60 minutes.
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Almeras, Xavier. "Optimisation de la tenue au feu d'une formulation intumescente du polypropylène pour applications dans les transports terrestres." Lille 1, 2003. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2003/50376-2003-159.pdf.
Full textAbstract:
Dans une première partie, le mélange polypropylène/polyamide-6/polyphosphate d'ammonium (PP/PA-6/APP) est optimisé. L'efficacité du mélange PA-6/APP dans le PP est mise en évidence. La présence d'un agent interfacial indispensable pour prévenir les phénomènes de rejet est démontrée. Une forte influence des conditions de mise en oeuvre (température, cisaillement, temps de résidence) par les différents procédés d'élaboration (malaxage, extrusion) apparaît au cours de cette étude. Le rôle de l'agent interfacial et la recherche d'un effet de synergie complètent cette partie pour répondre à un cahier des charges précis. Les possibilités de mise en oeuvre par extrusion puis injection-moulage du mélange sont vérifiées. La seconde partie de l'étude est consacrée à l'étude de l'évolution des propriétés du matériau lorsqu'il est soumis à un vieillissement accéléré. Les résultats obtenus sont comparés à l'influence d'extrusions successives. La dégradation des performances est expliquée par une analyse morphologique et une analyse élémentaire. Le mécanisme d'oxydation du PP est abordé. La troisième partie de ce travail porte sur l'influence de l'ajout de charges minérales comme renfort sur les propriétés mécaniques et la tenue au feu du mélange. L'influence des caractéristiques physico-chimiques du talc et du carbonate de calcium est mise en évidence. Le rôle du procédé de mise en oeuvre, notamment du nombre d'extrusion sur le comportement du mélange lorsqu'il est soumis à différents tests feu complète la troisième partie.