Dissertations / Theses on the topic 'Matériaux polymères isolants'
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Pouillès, Véronique. "Caractérisation diélectrique de matériaux composites isolants : contribution à la modélisation de leur vieillissement." Toulouse 3, 1995. http://www.theses.fr/1995TOU30109.
Full textLahoud, Nadine. "Modélisation du vieillissement des isolants organiques sous contrainte électrique : application à la fiabilité des matériaux." Toulouse 3, 2009. http://thesesups.ups-tlse.fr/517/.
Full textThe aim of this study is to improve the description of solid organic insulators or polymers ageing under electrical stress. With this objective in view, the different ageing scenarios existing in the literature were analyzed, compared and improved. This theoretical study showed that many parameters related to their heterogeneous structure and the distribution of their properties were neglected in order to simplify the modelling. This study presents a new approach in the description of solid organic insulators ageing by taking into consideration their experimentally demonstrated structural complexity. In this approach, the polymer material has been assimilated to a set of sites representing different energy states, thereby different properties as well as ageing rates depending on each site. The principal parameters involved during the ageing process, such as the specific volume variation, the dielectric strength evolution and the local value of the electrical field have been defined. The expression of the retardation time specific to each elementary ageing process has been established. Finally, a distributed form of those retardation times has been presented. Our "phenomenological" approach is thus a multi-sites one permitting, along with an experimental study, to establish an equation relating the life time of polymer electrical insulators to the different parameters at play, all along respecting their distribution over the entire set of sites within the polymer
Bellomo, Jean-Philippe. "Etude des conséquences des nouvelles formes de commande sur les matériaux de l'isolation statorique." Toulouse 3, 1996. http://www.theses.fr/1996TOU30067.
Full textEl, Ourzaz Lahcen. "Mesures diélectriques et caractérisation de matériaux moléculaires." Lyon 1, 1989. http://www.theses.fr/1989LYO10064.
Full textSilva, Igor. "Propriétés des matériaux isolants pour application dans les appareillages moyenne tension à tension continue." Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALT043.
Full textRecent advancements in direct-current technology from the high-voltage transport and low-voltage consumption have brought medium-voltage DC (MVDC) to the forefront. This thesis delves into the insulating DC properties of two commonly used materials in distribution equipment: epoxy filled with silica and silicone rubber.In a monolayer configuration, each material underwent extensive investigation, focusing on water sorption characteristics and electrical conduction. Current measurements were conducted to analyze conduction under various fields, temperatures, and water uptake conditions. Additionally, the Laser Pressure Pulse (LIPP) method was employed for space charge measurements as a complementary technique. The study extended to a bilayer configuration, combining both materials, with insights from monolayer experiments informing the properties of the bilayer and predicting field distribution.The DC conduction in epoxy exhibited high dependence on water absorption, with moisture influencing non-linearity and altering the conduction mechanism. Conversely, silicone demonstrated electrode-limited conduction, with current variations tied to water sorption through a saturation-limited mechanism. In a hypothetical bilayer configuration, where epoxy represents a type-C bushing and silicone serves as the cable termination, the field is expected to concentrate in the epoxy in dry environments, shifting to silicone as humidity increases. The thesis concludes with discussions on material selection strategies and the design of multi-layer configurations
Schieda, Mauricio. "Elaboration par CVD plasma et caractérisation de matériaux pour pile à combustible à membrane alcaline." Montpellier 2, 2007. http://www.theses.fr/2007MON20202.
Full textMillière, Laurent. "Maîtrise des interfaces pour le contrôle de l'injection de charges dans les polymères isolants électriques." Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30317/document.
Full textCharge injection phenomenon in electrically insulating polymers and the resultant electric field distortion remain obstacles to the development of cables for electrical energy transport under high voltage direct current (HVDC). Routes to solve the problem are most often looked for by acting on the material formulation, polyethylene in the present case. As alternative route, we explore in this thesis the possibility to develop a barrier layer allowing fine control of the charge injection in low density polyethylene (LDPE) films. The proposed and further studied solution is to tailor the surface of the polymer film by introducing metallic nanoparticles that would act as deep traps and would produce field screening, thus controlling charge injection. To achieve this, silver nanoparticles (AgNPs) are deposited on the LDPE and covered by a thin organosilicon layers of the type SiOxCy:H. The nanocomposite layer with total thickness of about 50 nm is elaborated in a plasma process. The AgNPs are obtained by sputtering of a silver target and the organosilicon matrix is then deposited in a plasma enhanced chemical vapor deposition (PECVD). The deposition process is realized in the same reactor in the plasma of an asymmetric RF capacitively coupled discharge maintained at 13.56 MHz at low gas pressure. The obtained characteristics for the AgNPs are for their mean size, density and dispersion. The physico-chemical and structural analyses of the nanocomposite layer allowed identifying the plasma operating conditions to control the AgNPs properties. From the evaluation of the efficiency of the AgNPs/organosilicon stack against charge injection, a detailed description of the required properties of the nanocomposite layer for the control of the charge injection phenomenon was derived. The behaviour of the studied structure, nanocomposite layer deposited on the surface of LDPE film, under electrical stress was studied by space charge measurement through the Pulsed Electro-Acoustic (PEA) method, current and surface potential decay measurements. The obtained results show that tailoring the surface of polyethylene film by very thin nanocomposite layer containing AgNPs embedded at a controlled distance from the free surface of the organosilicon matrix permits suppression of charges injection in LDPE films. The impact of nanocomposite layer structure on the efficiency of the barrier effect was evaluated. The mitigation effect is observed up to the typical service electric field for HVDC applications. This study presents a proof-of-concept and opens the way for interface tailoring to control the charge injection in electrically insulating polymers
Vallée, Franck. "Durabilité des composites polymères/ciment : application au cas des enduits minces sur isolants." Grenoble INPG, 1999. http://www.theses.fr/1999INPG0138.
Full textAmbid, Matthieu. "Evaluation de nanocomposites polypropylène/silicate pour l'isolation électrique : étude des phénomènes de polarisation, de conduction et des propriétés optiques." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/795/.
Full textThis thesis focuses on polyolefin matrix nanocomposite. The goal is to provide an interpretation on their macroscopic properties. We studied electrical properties, optical and chemicophysical properties of composite materials based on iso- and syndiotactic polypropylene matrix and dispersions belong to the generic class of silicates. The means employed on measures dynamic dielectric analysis, current in the time domain, electroluminescence, photoluminescence and UV-visible spectroscopy. A method of time-frequency inversion was implemented : it allows to explain the transient currents observed from the frequency data and identify the regimes of field where nonlinear phenomena occur
Lefebvre, Jérôme. "Etude et valorisation d'un absorbant innovant à base de polymères d'origine naturelle dédié au confort acoustique." Thesis, Artois, 2018. http://www.theses.fr/2018ARTO0201/document.
Full textThis thesis is about acoustic comfort and deals particularly with absorptive materials used to treat noise pollution in the housing environment. Our purpose is a double-sided one as the idea is to propose a bio based and absorptive material within the range of low frequencies.We have focused on porous bio based material on the same manufacturing process of porous ceramic. It is composed of homogeneous and isotropic cellulose. The making of a polymethyl methcrylate print enabling a thorough control of its internal structure. Then, we have dealt with the experimental characterization of its acoustic properties and of the intrinsic parameters of the material. The analysis of these data together with the numerical modelling permitted to define the physical characteristics having an influence on acoustic performances and to identify their means of improvement.Finally, the implementation of empirical means will be presented, namely: (i) the inclusion of aerogel in the porous mould, (ii) the exploitation of double porosity in two different configurations, either in the case of cellulose/aerogel composite, or the one of a material composed of a double mesoporous/microporous structure and (iii) the use of materials containing gradients of properties (interconnection or porosity). For each of these three approaches, the manufacturing process and the characterization of these new materials are detailed and their acoustic performances are discussed
El, Yamani Hamza. "Caractérisation du comportement mécanique de matériaux isolants sous choc." Electronic Thesis or Diss., Bourges, INSA Centre Val de Loire, 2021. http://www.theses.fr/2021ISAB0007.
Full textRisk reduction on Seveso sites, particularly for the protection of industrial buildings in the event of an explosion scenario, is a matter of concern. In the context where the insulation of industrial buildings is becoming more widespread, one solution would be to combine thermal insulation and building protection, by exploiting the absorption capacity of common thermal insulation materials. This solution would be interesting from an economic point of view.The aim of this PhD thesis is to experimentally characterise the mechanical behaviour of two insulating materials commonly used in France: a polyisocyanurate foam and a glass wool. Various devices were used to determine the mechanical behaviour, in particular the Split Hopkinson Pressure Bars device, which allows to characterise the mechanical behaviour at high speed loading.The polyisocyanurate foam was characterised in static and dynamic regimes, in unconfined compression and confined compression. These tests showed a sensitivity to the strain rate of the plateau stress in the material, and showed, by using the digital image correlation technique, the heterogeneity of the deformation in the material. The behaviour of the foam was modelled in two ways: firstly with an empirical law and secondly with a rheological model to simulate a dynamic compression test. The glass wool was characterised in simple static compression, and its behaviour was modelled empirically.The modelling based on empirical laws allowed us to carry out some simple simulations of a dynamic stress of explosion type on a cladding-material-structure assembly. The rheological model, which only concerns the polyisocyanurate foam, was used to identify the viscoplasticity coefficient
Guffond, Raphaël. "Characterization and modeling of microstructure evolution of cable insulation system under high continuous electric field." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS039/document.
Full textThis thesis presents a research work on understanding and modeling the electrical behavior of insulation system in cables subjected to high DC constraints. Electrical properties of polymeric insulation are directly related to their chemical and physical heterogeneities present at several scales. In this work, a new model is developed to simulate the modification over time of the microstructure in insulation polymers under electric field and temperature as well as the subsequent impacts on electrical properties. In this model, matrices are used to describe the distribution of each heterogeneity and electrical property in semi-crystalline polymer. When stressed under electric field and at temperature, matrices of microstructure evolve from implemented genetic laws. This simulated microstructure evolution yields to the simulation of electrical property changes over time at transient and steady state. To define these genetic laws, a detailed characterization of the physical, chemical and electrical properties of specific materials as a function of temperature and electric field is experimentally performed. Genetic laws are notably implemented to take into account the impact of the semi-crystalline structure and the presence of chemical residues in polymer electrical properties. Based on these genetic evolution laws, this modeling approach allows simulating DC electrical behavior of polymers only from their physical and chemical characterizations and reproduce accurately experimental electrical behavior with a faster solving time compared to other simulation methods
Bouynet, Enmmanuelle. "Propriétés diélectriques large bande de matériaux à basse température : application à l'étude de composés de la famille des fullerènes et de composites isolant-polymère conducteur." Bordeaux 1, 1996. http://www.theses.fr/1996BOR10690.
Full textDuffour, Emmanuel. "Interaction plasma-isolant. Applications au lanceurélectrothermique et à l'interaction SF6-polyéthylène." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2000. http://tel.archives-ouvertes.fr/tel-00011655.
Full textUne étude fondamentale de la dynamique moléculaire, basée sur l'utilisation des méthodes numériques particulières comme les intégrateurs symplétiques et l'exploitation des différents potentiels d'interactions existants (Morse, Lennard-Jones...), a abouti à deux modèles de polymère : le polyéthylène ou PE (CH2)n. Le premier modèle dit simplifié consiste à considérer un groupement CH2 comme un atome fictif de masse molaire 14g, tandis que le second plus complet traite la dynamique de l'atome d'hydrogène au sein de la macromolécule. Ces deux modèles sont utilsés, dans le cadre de ce travail, pour diverses interactions.
Par ailleurs, des mesures expérimentales de perte de masse des matériaux polymères qui interagissent avec un plasma, créé par l'explosion d'un fil de cuivre, sont exposées. Ces résultats sont corrélés par des calculs théoriques de thermodynamique qui montrent une différence de comportement des deux polymères testés : le polyéthylène et le polyoxyméthylène, POM ou Delrin (CH2O)n.
Douar, Adnane. "Recherche de matériaux isolants pour la conception d'une nouvelle génération de connecteurs électriques haute tension : influence de la pollution sur les phénomènes de décharges partielles du contournement et de claquage." Thesis, Ecully, Ecole centrale de Lyon, 2014. http://www.theses.fr/2014ECDL0046/document.
Full textIn the present study, we deal with an essential problem related to electrical lines accessories and more particularly to piercing connectors (TTDC 45501FA) commercialized by a private company named Sicame and which is located in Arnac-Pompadour (Corrèze, France). This product/accessory is designed to provide power diversions on medium voltage live lines HVA operating between 15 and 25kV. However, it becomes required to design a new generation of piercing connectors able to operate on 52kV live lines because of the electrical power demands that are steadily increasing. Actually, the main concerns about these products are the occurrence of partial discharges within the insulating material volume (polyamide 6 containing 50%wt of glass fibers). Most of the time, these discharges induce an early ageing process of the accessory under the combined effects of a corrosive environment (as salt fog) and an electric field threshold. Thus, the main objective of the present Ph.D. thesis is to carry out an appropriate choice of insulating materials among several tested polymers such as thermoplastics and thermosetting epoxy resins and EPDM elastomers that are capable of withstanding several constraints: thermal and electrical and mechanical and chemical conditions. The experimental section is focusing on the measurements of flashover voltage and partial discharges activity propagating on polymeric surfaces and breakdown voltage within material bulks under A.C voltage. That is why polymeric samples with plane surfaces and textured surfaces are molded to compare their resistance to partial discharges when being subjected to polluted environments such as salt fog; these measurements are necessary to choose the suitable materials for the required application to be integrated in the new generation of connectors. Then, the optical and electrical characterization results of creeping discharges propagating on several polymeric surfaces under lightning impulse (L.I.) voltage with its both polarities (positive and negative) and for two kinds of applied electric field (normal and tangential) are presented in the case of solid/air interfaces. Final length measurements of creepage discharges are the main parameter for distinguishing material properties. The whole obtained results (under AC and LI voltages) allow us to point out the cycloaliphatic epoxy resins as potential candidates to the conception of a new generation of piercing connectors. In addition, the electric field simulation and modelling of the TTDC 45501FA connector by using the Flux 2D/3D software seems to be helpful to design a connector prototype which exhibits a new geometry and is able to reach a voltage level that equals 52kV
Lacoste, Clément. "Mousses rigides de tannins de type procyanidine : formulation et caractérisation." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0259/document.
Full textRigid foams contitute a very important class of materials considering their wide application range and their considerable economic impact. The development of tannin-based foams provided materials made from 90% natural products.In this work, a type of tannins highly reactive, namely « procyanidin », was used. First, tannins composition and reactivity were studied. Then, the foaming process investigation of tannin-based resins leads to a wide pannel of tannin-furanic rigid foams. Their excellent fire resistance, mechanical resistance and high thermal performance make them high quality insulation materials. These foams are also suitable for other applications such acoustic absorption. Thus, new cellular solids from tannin and protein were also developped, offering a new type of materials derived from natural products
Desmars, Loriane. "Etude des propriétés électriques et thermiques de matériaux composites à matrice époxy-anhydride pour l'isolation haute tension." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI021.
Full textThe integration of renewable energies to the power grid requires its modification in order to ensure its stability, security and efficiency. Improving ultra-high voltage alternative current (UHVAC) gas insulated substations (GIS), e.g. reducing their size or increasing their voltage, is one of the challenges induced by the development of the future power grid, the supergrid. Increasing the ability of solid insulators used in such equipment to withstand electro-thermal stress has been identified as the main obstacle to overcome. The work presented in this manuscript has been motivated by the necessity to develop more efficient electrical insulating materials compared to commercially available ones. An epoxy-anhydride matrix filled with micron sized alumina, often used to produce GIS solid insulators, has been used as a reference for this study. We decided to keep the matrix of the reference material throughout our work and to concentrate on the filler influence in order to optimize the properties of the composites. The impact of the nature of the filler (alumina or hexagonal boron nitride), its shape factor (platelets or almost spherical particles) and its volume fraction upon thermal conductivity, coefficient of thermal expansion, dynamic mechanical properties, dielectric properties, high voltage direct current (DC) conductivity and AC breakdown strength have been highlighted. The experimental study of structure-property relationships is completed by dielectric properties and thermal conductivity modelling using the effective medium theory
Honoré, Mathilde. "Mise au point de nouveaux bio-composites verts innovants à base de roseau commun Phragmites australis : applications en plasturgie et en éco-construction pour le bâtiment." Thesis, Lorient, 2020. http://www.theses.fr/2020LORIS572.
Full textThe use of plant fibres, both in the field of plastics processing and in the building industry, makes it possible to reduce greenhouse gas emissions and therefore the environmental impact of mankind. Interest in biocomposites using plant fibres such as hemp, wood, flax and also miscanthus reed is increasing. Nowadays, there is very little work on the reed phragmites australis. However, as it does not use cultivated areas, this invasive plant is independent of agricultural issues and does not require any chemical inputs. The reed harvest is therefore part of a wetlands management approach while enhancing the value of a material with multiple properties. This work is devoted to the characterisation of the raw material phragmites australis and to the study of its eligibility as a substitute material of three reference materials, wood, miscanthus and hemp shiv, widely used as reinforcements in plastics processing and eco-construction. Composite formulations using two polymer matrices (polypropylene and polybutylene succinate) with different rates of plant fillers and coupling agent were characterised from the point of view of their mechanical properties by Charpy tensile, flexural and impact tests. The water ageing of these composites was also studied and correlated to the hydrophobic character of the reed. For the construction application, formulations based on reeds of different origins and using different binders (lime, plaster and earth) were tested in compression and with thermal conductivity measurements in order to evaluate the behaviour of the reed as a material for building use