Dissertations / Theses: 'Polyethylene terephthalate'

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Matthews, Richard Gary. "The biaxial drawing of polyethylene terephthalate." Thesis, University of Leeds, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410647.

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Al-Azzawi, Farah. "Degradation studies on recycled polyethylene terephthalate." Thesis, London Metropolitan University, 2015. http://repository.londonmet.ac.uk/917/.

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This project aims to investigate the influence of UV on the properties under natural and artificial weathering. The real-time outdoor weathering exposures provide the most accurate results but, they are very slow and manufacturers cannot afford to wait in order to see if a new or improved product formulation is really an improvement. So, accelerated testing methods are designed to simulate natural weathering with the combined action of the most weathering damaging factors; UV radiation, oxygen, temperature and water. Whatever the application, there is a concern regarding the durability of the products because if its useful lifetime can be estimated in short time, their maintenance and replacement can be planned in advance. In this study, recycled PET samples were exposed to UV outdoors and to accelerated weathering up to 13,000 hr. The mechanical behaviour (tensile and impact), thermal behaviour (DSC), molecular structure analysis (FTIR), flow characteristics (MFI) and surface properties (colour and gloss) of the samples were investigated. The whole body of the samples was substantially unaffected by degradation for long exposure time and this is confirmed by MFI and DSC results. However, the surface of the samples is affected which is seen in FTIR analysis, colour and gloss change. This explains that the photodegradation is a surface effect. FTIR analysis shows an increase in the gauche ratio and decrease in the trans ratio for both types of weathering indicating a less ordered structure after the UV radiation due to chain scission by Norrish Type I and II mechanism. Carboxylic acid is formed as a result of degradation and increases with the extent of UV exposure in both types of weathering, the formation of carboxylic acid by Norrish II is dominated over Norrish I. Colour and gloss measurement shows that the effect of degradation takes place strongly in the first 2000 hr of exposure in natural weathering and extended up to 5000 hr in accelerating weathering due to the formation of microcracks. Mechanical tests show that the UV effect was not significant on bulk properties such as yield stress and elongation at yield for accelerated weathering samples up to 1000 hours, then dropped by 62% and 57% respectively up to 13000hr of exposure and remained unchanged for the whole period of exposure for outdoors samples. The drop in the failure stress and elongation at failure for accelerated weathering samples right from the beginning indicate the formation of microcracks is from the early stages of exposure. For outdoor samples, failure stress remained unchanged for the first 1000 hr of sunlight exposure, then decreases progressively with increasing exposure in the environment. The elongation to failure is unchanged up to 13000 hours. After 13000 hrs of exposure to sunlight, r-PET samples failed to break while those exposed to UV lamps failed in a brittle manner under impact after 250 hrs and this indicates the transition from ductile to brittle behaviour just after 10 days of accelerated UV exposure because of crack formation. For accelerated weathering samples, the impact strength remained unchanged in the first 1000 hr of exposure, then a decrease up to 5000 hr of exposure when the effects of flaws become significant and dropped sharply by 85% after 5000hr of exposure. The correlation between both types of weathering shows that one year in natural weathering is equivalent to one and a half months in accelerated weathering according to colour measurements. The effect of accelerated weathering is much bigger than the natural weathering and this is due to higher radiation dosage, temperature and humidity during the test which accelerate chain scission rate that lead to faster crack growth.

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Zhu, Zhengmao. "Photochemical modification of polyethylene terephthalate surface." W&M ScholarWorks, 2005. https://scholarworks.wm.edu/etd/1539623471.

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The prospect of obtaining desired surface-mediated characteristics while retaining bulk-mediated physical properties and avoiding potential environmental issues with wet chemical technology lends considerable appeal to photochemical approaches to surface modification.;We undertook a combined experimental and computational approach to investigate the effect of deep UV irradiation on the polyethylene terephthalate (PET) surface. its response to 172 nm UV from a xenon examiner lamp in the absence of oxygen was characterized with X-ray Photoelectron Spectroscopy (XPS), Time of Flight/Secondary Ion Mass Spectrometry (ToF/SIMS), transmission infrared spectroscopy (IR), and Atomic Force Microscopy (AFM). The surface chemistry details suggested that the primary photochemical reactions involved a Norrish type I based decarbonylation and a Norrish type II process yielding terminal carboxylic acid groups, consistent with the possible photochemistry from n-pi* type lowest singlet excited states of PET according to the computational modeling results. By directly populating n-pi* type excited states, 172 nm UV promoted effective surface photochemistry of PET with further helps from the high UV absorptivity and the high surface mobility of the molecules.;Utilizing this active surface radical chemistry, a new grafting strategy was developed to impart desirable functional properties to the surface. A broad range of grafting chemicals can be employed in their vapor forms, demonstrated with an alkene or an alkane. Surface analysis with XPS, ToF/SIMS, AFM, and water contact angle measurements confirmed the effectiveness of the approach, supporting the notion of the surface radical initiated processes.;A potentially useful anti-stain/soil coating was developed by grafting with a fluorocarbon species. Surface analysis suggested that the grafted fluorocarbon formed a nano-scale self-assembled monolayer. The coating had a similar water contact angle as that of a pure fluoropolymer but a better oil repellency due to the special molecular orientation in the graft layer.;A potential antimicrobial application was demonstrated with amine chemicals. Structure characterization and computational modeling results suggested that the photochemistry of the UV active grafting chemicals also played an important role in the grafting process. A double bond structure in the amine species protected the amine functional groups and the resulting coating demonstrated antimicrobial activity against E. coli.

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Kegel, Mark. "Fibres from recycled post consumer PET/nylon 6 blends." Australasian Digital Thesis Program, 2006. http://adt.lib.swin.edu.au/public/adt-VSWT20070606.111448/index.html.

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Thesis (PhD) - Swinburne University of Technology, Industrial Research Institute Swinburne - 2006.
A thesis submitted to Industrial Research Institute Swinburne in fulfilment of the requirements for the degree of Doctor of Philosophy, Swinburne University of Technology - 2006. Typescript. "July 2006". Includes bibliographical references (p. 147-156).

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Leung, Ka-po Filipe, and 梁嘉保. "Structural development of polyethylene terephthalate (PET) through solid-state drawing and annealing." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B26648891.

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Matthews, Thomas Robert. "Surface Properties of Poly(ethylene terephthalate)." University of Toledo / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1177515548.

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Toufaili, Faissal-Ali el. "Catalytic and mechanistic studies of polyethylene terephthalate synthesis." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=979236096.

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SENEZ, PHILLIPE CAMPELLO. "BEHAVIOR OF POLYETHYLENE TEREPHTHALATE (PET) FIBERS REINFORCED SAND." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2016. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=27669@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
PROGRAMA DE EXCELENCIA ACADEMICA
O presente estudo teve como principal objetivo demonstrar que fibras derivadas da reciclagem de garrafas PET (Polietileno Tereftalato), confeccionadas com 100 porcento do resíduo, pela indústria têxtil, podem ser uma boa alternativa se utilizadas como reforço de solos, quando submetidos a diferentes níveis de cargas. Buscando uma melhor aplicabilidade para este material, foram executados ensaios de compressão triaxial drenados em laboratório, bem como ensaios de prova de carga em placa e também com simulação de um talude em modelo físico reduzido, para a determinação do comportamento mecânico de uma areia e do compósito areia-fibras PET. Para os ensaios triaxiais drenados, foram utilizadas fibras PET com dois títulos (correspondente ao diâmetro das fibras) e comprimentos distintos (1,4 dtex com 38 mm e 3,3 dtex com 56 mm), inseridas aleatoriamente na massa de solo, onde foi utilizado o teor de 0,5 porcento de fibras, em relação ao peso seco do solo, teor de umidade de 10 porcento e densidade relativa de 50 porcento. Os resultados mostraram que o comportamento da areia pura é influenciado pela adição de fibras PET, melhorando os parâmetros de resistência, como o intercepto coesivo e o ângulo de atrito, definidos pelo critério de Mohr-Coulomb. O compósito reforçado com as fibras PET de menor título e menor comprimento apresentou um maior ganho na resistência ao cisalhamento, mas ambos os compósitos, em comparação ao solo não reforçado, apresentaram uma maior resistência. Para os ensaios de prova de carga em placa e para a simulação do talude, ambos realizados em modelo físico reduzido, foram utilizadas as fibras de menor título e menor comprimento como elemento de reforço. Observa-se que a inserção das fibras PET melhora o comportamento carga-recalque da areia pura, onde o compósito reforçado apresenta uma maior capacidade de suporte e a redução dos recalques, bem como uma mudança na propagação e formação das fissuras ao redor da placa. Na simulação do talude, a inserção das fibras PET promove uma alteração completa no mecanismo de ruptura ocorrido no compósito, quando comparado à ruptura da areia pura. Ressalta-se o emprego positivo das fibras PET para aplicação como reforço de solos em obras geotécnicas (como por exemplo, em camadas de aterros sanitários, aterros sobre solos moles, reforço de taludes, base de fundações superficiais e controle de erosão), além de eliminar problemas atuais de disposição de resíduos, dando um fim mais nobre a este material, com benefícios ambientais, sociais e econômicos.
The main objective of this study was to demonstrate that fibers derived from the recycling of PET (Polyethylene Terephthalate) bottle, 100 percent made from the residue by the textile industry, can be a good alternative if used as reinforcement of soil, when submitted to different load levels. Looking for a better applicability for this material, were executed drained triaxial compression tests in laboratory, as well as plate load tests, also with slope simulation in a reduced physic model, to evaluate the mechanical behavior of a sand and a composite sand-PET fibers. For the drained triaxial tests, were used PET fibers with two different titles (corresponding to the fiber diameters) and lenghts (1,4 dtex com 38 mm e 3,3 dtex com 56 mm), distributed randomly in the soil mass, where was used a fiber contente of 0,5 percent by relation to the soil s dry weight, moisture content of 10 percent and relative density of 50 percent. The results showed that the pure sand behavior was influenced by the addition of PET fibers, improving the strenght parameters as the cohesion intercept and the friction angle, defined by the Mohr-Coulomb criteria. The composite reinforced with PET fibers with minor title and lenght presented a better improvement in the shear strenght, but both composites, compared to the non reinforced soil, showed greater resistence. For the plate load tests and for the slope simulation, both performed in a reduced physic model, it was used the fiber with minor title and lenght as reinforcement element. The addiction of PET fibers improve the load-settlement behavior of the sand, where the reinforced composite shows a greater bearing capacity, a reduction of the settlements and a change in the propagation and formation of fissures around the plate. In the slope simulation, the addiction of PET fibers promove a complete alteration in the rupture mechanism that occurred in the composite, when compared to the rupture of the pure sand. It is highlighted the positive use of PET fibers for application as soil reinforcement in geotechnical works (as an example, in landfill layers, embankment on soft soil, slope reinforcement, base of shallow foundations and erosion control), eliminating current problems of waste disposal, giving a noble end to this material, with environmental, social and economical benefits.

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Matthews, Thomas R. "Surface properties of poly(ethylene terephthalate) /." Connect to Online Resource-OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1177515548.

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Thesis (M.S.Ch.E.)--University of Toledo, 2007.
Typescript. "Submitted as partial fulfillment of the requirements for The Masters of Science Degree in Chemical Engineering." Bibliography: leaves 76-77.

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Boyd, Timothy Joseph. "Transient crystallization of poly(ethylene terephthalate) bottles /." See Full Text at OhioLINK ETD Center (Requires Adobe Acrobat Reader for viewing), 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1091111913.

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Dissertation (Ph.D.)--University of Toledo, 2004.
Typescript. "A dissertation [submitted] as partial fulfillment of the requirements of the Doctor of Philosophy degree in Engineering." Bibliography: leaves 244-251.

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Al-Fouzan, Abdulrahman M. "Polyethylene Terephthalate / clay nanocomposites. Compounding, fabrication and characterisation of the thermal, rheological, barrier and mechanical properties of Polyethylene Terephthalate / clay nanocomposites." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5283.

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Polyethylene Terephthalate (PET) is one of the most important polymers in use today for packaging due to its outstanding properties. The usage of PET has grown at the highest rate compared with other plastic packaging over the last 20 years, and it is anticipated that the increase in global demand will be around 6% in the 2010-2015 period. The rheological behaviour, thermal properties, tensile modulus, permeability properties and degradation phenomena of PET/clay nanocomposites have been investigated in this project. An overall, important finding is that incorporation of nanoclays in PET gives rise to improvements in several key process and product parameters together - processability/ reduced process energy, thermal properties, barrier properties and stiffness. The PET pellets have been compounded with carefully selected nanoclays (Somasif MAE, Somasif MTE and Cloisite 25A) via twin screw extrusion to produce PET/clay nanocomposites at various weight fractions of nanoclay (1, 3, 5, 20 wt.%). The nanoclays vary in the aspect ratio of the platelets, surfactant and/or gallery spacing so different effect are to be expected. The materials were carefully prepared prior to processing in terms of sufficient drying and re-crystallisation of the amorphous pellets as well as the use of dual motor feeders for feeding the materials to the extruder. The rheological properties of PET melts have been found to be enhanced by decreasing the viscosity of the PET i.e. increasing the 'flowability' of the PET melt during the injection or/and extrusion processes. The apparent shear viscosity of PETNCs is show to be significantly lower than un-filled PET at high shear rates. The viscosity exhibits shear thinning behaviour which can be explained by two mechanisms which can occur simultaneously. The first mechanism proposed is that some polymer has entangled and few oriented molecular chain at rest and when applying high shear rates, the level of entanglements is reduced and the molecular chains tend to orient with the flow direction. The other mechanism is that the nanoparticles align with the flow direction at high shear rates. At low shear rate, the magnitudes of the shear viscosity are dependent on the nanoclay concentrations and processing shear rate. Increasing nanoclay concentration leads to increases in shear viscosity. The viscosity was observed to deviate from Newtonian behaviour and exhibited shear thinning at a 3 wt.% concentration. It is possible that the formation of aggregates of clay is responsible for an increase in shear viscosity. Reducing the shear viscosity has positive benefits for downstream manufacturers by reducing power consumption. It was observed that all ii three nanoclays used in this project act as nucleation agents for crystallisation by increasing the crystallisation temperature from the melt and decreasing the crystallisation temperature from the solid and increasing the crystallisation rate, while retaining the melt temperature and glass transition temperatures without significant change. This enhancement in the thermal properties leads to a decrease in the required cycle time for manufacturing processes thus potentially reducing operational costs and increasing production output. It was observed that the nanoclay significantly enhanced the barrier properties of the PET film by up to 50% this potentially allows new PET packaging applications for longer shelf lives or high gas pressures. PET final products require high stiffness whether for carbonated soft drinks or rough handling during distribution. The PET/Somasif nanocomposites exhibit an increase in the tensile modulus of PET nanocomposite films by up to 125% which can be attributed to many reasons including the good dispersion of these clays within the PET matrix as shown by TEM images as well as the good compatibility between the PET chains and the Somasif clays. The tensile test results for the PET/clay nanocomposites micro-moulded samples shows that the injection speed is crucial factor affecting the mechanical properties of polymer injection moulded products.

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Thistlethwaite, T. "Crystal deformation and structure of oriented poly(ethylene terephthalate), poly(pentamethylene terephthalate) and polyethylene." Thesis, University of Leeds, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355475.

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Neilson, Alan Finlay. "Synthesis and characterisation of branched poly(ethylene terephthalate)s." Thesis, University of Strathclyde, 1999. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21173.

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This report details the work carried out on the synthesis and characterisation of branched polyesters. The experimental effort concentrated on the branching of PET-type polymers with a variety of potential branching agents, such as trimesic acid, and the control of branching with end-capping agents, such as benzyl alcohol. The polymers synthesised were then characterised by solution viscosity, end-group analysis, DSC analysis, theological analysis and light scattering. Extensive branching of polymers has been observed and controlled via end-capping agents. One group of polyesters synthesised with increasing levels of brancher, were characterised by absolute Mw values which increased from -10K to -350K. Despite this, all of the macromolecules displayed roughly the same solution viscosity. Though the corresponding melt viscosity increased with Mw, the values achieved were far below those expected for analogous linear polymers of comparable Mw. A second group of polyesters synthesised with a fixed level of brancher and increasing levels of end-capper were characterised by a much narrower range of Mw values. These polymers however had melt viscosities lower than those of linear polymers yet had Mw's of between -3 and - 15 times greater than those of linear polymers.

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Yang, Shuying. "Analysis of poly(ethylene terephthalate) fibers using polarized raman microscopy." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/8310.

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Andrade, Genara Selene. "New comonomers and pet-based copolymers for functional high-barrier applications." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/29899.

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Kirov, Kiril. "Surface structure of oriented PET films." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393384.

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Kurtulus, Ceren. "Self Reinforcement Of Poly(ethylene Terephthalate) And Polyethylene Blends." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12608306/index.pdf.

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In this study, 20/80 (weight %) Poly(ethylene terephthalate) (PET) /High Density Polyethylene (HDPE) Microfibrillar Reinforced Composites (MFC) were prepared by using high density polyethylene (HDPE) as the matrix material, poly(ethylene terephthalate) (PET) as the reinforcing component. Ethylene n-butyl acrylate-glycidyl methacrylate (E-nBA-GMA) and ethylene methyl acrylate (E-MA) as the compatibilizers in 1, 5, and 10 wt. %. The objective of this study is to produce MFCs based on PET and HDPE via extrusion-drawing-injection method and to characterize as extruded, as drawn and injection molded materials in terms of morphologies, and mechanical and thermal properties. In addition, the effect of compatibilizer type and content on properties of PET-HDPE composites was studied. For comparison purposes, conventional PET-HDPE composites with and without compatibilizer were prepared. Also, the effect of screw speed and drawing speed on the morphologies and mechanical and thermal properties were investigated. The effect of low and high injection temperature molding on morphologies were also observed. SEM analyses showed that, extruded blends became oriented after drawing. The fibrillar structure was preserved after injection molding. High injection molding temperature destroyed the structure of PET microfibers. In addition, it was also observed that the adhesion between HDPE and PET improved with the addition of the compatibilizers. Tensile strength and tensile modulus values of PET/HDPE MFCs increased with increasing drawing speed. Increasing the screw speed resulted in a slight decrease in tensile strength values. Addition of the compatibilizers to the system decreased tensile strength and tensile modulus values. Results of impact tests designated that the impact strength of the materials with and without MFC structure increased with the increasing amounts of E-nBAGMA. DSC analyses pointed out that, melting temperatures of HDPE and PET phase did not change significantly with increasing drawing speed or with the addition of the compatibilizer. As the drawing speed increased from 2.7 m/min to 6.2 m/min, degree of crystallinity of the drawn samples of the PET phase increased.

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Calmeyn, Timothy J. "Optimization of the melt-phase polyethylene terephthalate manufacturing process." Ohio : Ohio University, 1995. http://www.ohiolink.edu/etd/view.cgi?ohiou1179336415.

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Wiles, Robert Donald. "The thermal and thermo-oxidative degradation of polyethylene terephthalate." Thesis, Manchester Metropolitan University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320298.

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Yang, Yan. "Characterization of polyethylene terephthalate, cellulose acetate and their blends." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-03302010-020651/.

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Ganesan, Mohan. "Consequences of anisotropic deformation and crystallization in poly (ethylene terephthalate)." Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/11908.

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Malik, A. "Migration and sorption characteristics of refillable polyethylene terephthalate (PET) bottles." Thesis, London South Bank University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618654.

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Pattalachinti, Ravi Kumar. "Modeling and optimization of continuous melt-phase polyethylene terephthalate process." Ohio : Ohio University, 1994. http://www.ohiolink.edu/etd/view.cgi?ohiou1178728743.

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Maiorino, Lori Ann. "Enhanced infrared absorptance of polyethylene terephthalate via inorganic particulate additives." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/19906.

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Chilton, Tom. "Commercial Scale Recycling of Post-Consumer Polyethylene Terephthalate (PET) Waste." Thesis, Open University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520774.

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Dogan, Erkan. "Ter Blend Of Poly (ethylene Terephthalate), Polypropylene And Low Density Polyethylene." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1045574/index.pdf.

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This study covers the recycling of waste poly(ethylene terephthalate) (PET) bottles through melt blending with low density polyethylene (LDPE) and polypropylene (PP). In general, polymer blends are known to be immiscible and incompatible with poor mechanical properties. This problem is due to the low intermolecular forces between the components of the immiscible blends. In order to enhance the interaction and compatibility between these matrices, some reactive or non-reactive copolymers were used. In this work
PET was treated with silane coupling agent (SCA) (low molecular weight reactive additive) for compatilization of LDPE-PP-PET blends. LDPE-PP-PET blends were prepared in different compositions (by weight) with and without silane coupling agent at high temperatures by a single screw extrusion and injection molding. Mechanical properties of treated and non-treated blends were studied in terms of tensile strength, strain at break and impact strength. Melt flow properties of blends were investigated by melt flow index. The impact fractured surfaces and thermal behaviour of the blends were examined with Scanning Electron Microscope (SEM) and Differential Scanning Calorimeter (DSC), respectively. Through out the studies, good adhesion between PET and LDPE-PP matrix was successfully achieved by the surface treatment of PET particles. The adhesion was also observed in SEM studies. Also the variation in mechanical properties was found to be highly dependent on the number of extrusion.

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Mohanraj, Jagannathan. "Production and properties of die- drawn toughened polypropylene and polyethylene terephthalate." Thesis, University of Leeds, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250864.

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LOUZADA, NATHALIA DOS SANTOS LOPES. "EXPERIMENTAL STUDY OF SOILS REINFORCED WITH CRUSHED POLYETHYLENE TEREPHTHALATE (PET) RESIDUE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=25363@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
PROGRAMA DE EXCELENCIA ACADEMICA
O presente estudo apresenta o comportamento dos solos reforçados com PET em pó e triturado, através de ensaios de laboratório. Foram utilizados três solos: um solo coluvionar, uma areia limpa e mal graduada e uma bentonita. Caracterização física, química e ensaios mecânicos (triaxiais CIU e cisalhamento direto) foram realizadas para cada material e misturas. O ensaio triaxial foi realizado em amostras de solo argiloso compactado com porcentagens de pó de PET de 0, 10, 20 e 30 por cento de PET triturado de 3,0 e 5,0 por cento, por seco peso de solo. Os ensaios triaxiais, em amostras de areia foram feitas a uma densidade relativa de 50 por cento e 10 por cento de teor de umidade, e com 0, 10 e 20 por cento de pó de PET, em relação ao peso seco do solo. Os ensaios de cisalhamento direto com bentonita foram feitos com porcentagens de 0 e 30 por cento de pó de PET e 3,0 e 5,0 por cento de PET triturado, por peso seco de solo. Os resultados mostraram que o teor de PET e nível de confinamento têm influência sobre o comportamento mecânico final das misturas. Com ambos os resíduos de PET, as misturas apresentam um comportamento satisfatório, aumentando ou mantendo os parâmetros de resistência ao cisalhamento semelhantes ao solo puro. Assim, para as misturas argilosos, a mistura com 30 por cento de pó de PET e a com 5 por cento de PET triturado são mais eficazes, uma vez que nelas observou-se maior melhora nos parâmetros de resistência. Para misturas de areia a inclusão PET é mais eficaz com 10 por cento de pó PET em tensões confinantes menores e umidade ótima de 10 por cento. Para misturas bentonita, a inserção de PET é mais eficaz para o PET triturado na porcentagem de 5 por cento. Portanto, o uso de resíduos de PET para o reforço do solo poderia minimizar os problemas atuais disposição do resíduo, contribuir com a redução do consumo de recursos naturais e dar um uso nobre para este material.
This study presents the behavior of soils reinforced with crushed PET (Polyethylene Terephthalate) residue through experimental study. Three soils were used: a coluvionar soil, a clean and poorly graduated sand and a bentonite. Physical characterization, chemical and mechanical tests (isotropically consolidated-drained triaxial and direct shear) were performed for each material and mixtures. The triaxial test was performed on samples of clayey soil compacted within the maximum dry density and optimum moisture content with ratios of 0, 10, 20 and 30 per cent of fine crushed PET and 3,0 and 5,0 per cent of PET flakes, by dry weight of soil. The triaxial tests on sand samples were made to a relative density of 50 percent and 10 per cent of water content, and with 0, 10 and 20 percent fine crushed PET, by dry weight of soil. The direct shear tests with bentonite were made with ratios of 0 and 30 percent of fine crushed PET and 3,0 and 5,0 percent of PET flakes, by dry weight of soil. The results have shown that the PET content and level of confining stress have influence on the final mechanical behavior of the mixtures. With both residue of PET, the mixtures present a satisfactory behavior, increasing or maintaining the shear strength parameters similar to the pure soil. Thus, for the clayey mixtures, the fine crushed PET content of 30 percent and the PET flakes content of 5 percent are more effective, once they increase the strength parameters. For sandy mixtures the PET inclusions is more effective with 10 percent of fine crushed PET at lower confining stresses and the optimum content is 10 percent. For bentonite mixtures the PET inclusions is more effective for PET flakes and the optimum content is 5. Therefore, the use of PET waste for soil reinforcement could minimize the current problems of waste disposal, contribute with the reduction of consumption of natural resources and give a noble use for this material.

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Polishchuk, A. O., M. Ye Skyba, T. Tański, and O. S. Polishchuk. "Prospects of recycling polyethylene terephthalate waste into consumables for 3D-printers." Thesis, Київський національний університет технологій та дизайну, 2021. https://er.knutd.edu.ua/handle/123456789/19210.

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30

Kim, Soo Yeon. "Poly(ethylene terephthalate) filamentary materials for molding applications : processing and morphological considerations." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/11265.

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31

Konkol, Lidia, and lkonkol77@hotmail com. "Contaminant levels in recycled PET plastic." Swinburne University of Technology. Environment and Biotechnology Centre, 2005. http://adt.lib.swin.edu.au./public/adt-VSWT20051025.142051.

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The purpose of this thesis was to determine which contaminants were present in washed and dried shredded poly(ethylene terephthalate) (PET, flake) obtained from curbside collection and to determine whether their concentrations were above the US FDA threshold of 215 ppb. Over thirty semi-volatile contaminants were extracted from the treated flake by Soxhlet extraction using dichloromethane as a PET swelling solvent and gas chromatography-mass spectroscopy for identification and quantification. Soxhlet extraction of flake ground to 0-300 �m was effectively completed by 24 h, whereas sonication reduced the extraction time to 3 h. In contrast Soxhlet extractions on flake ground to a larger particle size range (>300-425 �m and >425-700 �m) were completed within four hours, possibly due to less aggregation in the extraction thimble. In the finely ground flake (0-300 �m) the levels of most contaminants were below 215 ppb, but six were not. Dodecanoic acid was present at about 1200 ppb, 2-butoxyethanol was approximately 1000 ppb, limonene, benzophenone and methylsalicylate were above 800 ppb and 2-methylnaphthalene near 215 ppb. After analogous method development the levels of all diffusible compounds in extruded PET pellets were below the threshold of 215 ppb. The Soxhlet extraction technique was validated by comparison with total dissolution by TFA for two of the three particle size ranges obtained by grinding the PET flake (>300-425 �m and >425-700 �m) and for the unground flake. Further validation was achieved by the comparison of contaminant levels determined by total dissolution with TFA and sonication with DCM using flake ground to the 0-300 �m size range. The levels of contaminants were found to increase with decreasing particle size range, but XRD measurements of degrees of crystallinity were similar for each PET particle size range, thus showing that the differences in contaminant levels were not due to variable percentages of the amorphous material from the tops and bottoms of shredded bottles, relative to the amounts of crystalline PET from the mid-sections of the bottles. Hence it was postulated that the variations in contaminant levels were due to selective grinding of the more highly contaminated surfaces, whilst the larger particles incorporated the less contaminated interior material. The analysis of the more homogenous annealed (extruded) pellets indicated that contaminant levels between the analogous particle size ranges were equivalent. This observation validated our interpretation of the high levels of contaminants found in finely ground flake being due to selective surface grinding where high levels are expected. When analysing volatiles, static headspace analysis was performed on flake and extruded pellets due to the limitations surrounding SPME. External standardisation was used as the method of quantification and the levels of toluene, undecane and p-xylene in extruded pellets were found to be below 38 ppb and therefore within the 215 ppb FDA-set threshold for flake and pellets.

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32

Cheng, Ka-lai Angie, and 鄭嘉麗. "The interfacial properties of PET/PP (20/80) microfibrillarcomposites." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31227223.

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33

Verhoyen, Olivier. "Crystallization of polyethylene terephthalate in injection moulding : experiments, modelling and numerical simulation." Université catholique de Louvain, 1997. http://edoc.bib.ucl.ac.be:81/ETD-db/collection/available/BelnUcetd-03032009-173159/.

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34

LeBoeuf, Leighton Lee Jr. "Investigation of rabid low temperature depolymerization of polyethylene terephthalate : a novel approach." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/8588.

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35

Lülsdorf, Nina Verfasser], Ulrich [Akademischer Betreuer] [Schwaneberg, and Lothar [Akademischer Betreuer] Elling. "Protein engineering for polyethylene terephthalate degradation / Nina Lülsdorf ; Ulrich Schwaneberg, Lothar Elling." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1125972815/34.

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36

Wei, Ren, and Wolfgang Zimmermann. "Biocatalysis as a green route for recycling the recalcitrant plastic polyethylene terephthalate." Universität Leipzig, 2017. https://ul.qucosa.de/id/qucosa%3A21102.

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37

Lülsdorf, Nina [Verfasser], Ulrich [Akademischer Betreuer] Schwaneberg, and Lothar [Akademischer Betreuer] Elling. "Protein engineering for polyethylene terephthalate degradation / Nina Lülsdorf ; Ulrich Schwaneberg, Lothar Elling." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1125972815/34.

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38

Ng, Robin. "Novel tissue scaffolds comprising nano- and micro-structures." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1196260817.

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39

Ma, Hongming. "Fiber spinning, structure and properties of poly(ethylene terephthalate-co-4,4' bibenzoate) copolyester fibers." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/8607.

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40

Qian, Li-Ren. "Characterization of polyethylene terephthalate heat set carpet yarn by near infrared reflectance spectroscopy." Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/9208.

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41

Labde, Rohan Khushal. "Preparation and Characterization of Polyethylene Terephthalate/Montmorillonite Nanocomposites by In-situ Polymerization Method." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1271126238.

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42

Joshi, Anup S. "Copolyesters and Terpolyesters of Polyethylene Terephthalate with Renewably Sourced Comonomers for Packaging Application." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1562943452866685.

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43

Kawakami, Osamu. "Accelerated embolization healing of aneurysm by polyethylene terephthalate coil seeded with autologous fibroblasts." Kyoto University, 2005. http://hdl.handle.net/2433/144741.

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44

Drucker, Steven M. "The suitability of polyethylene terephthalate copolyester for radiation sterilized dry small volume parenterals /." Online version of thesis, 1993. http://hdl.handle.net/1850/11896.

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45

Ophir, Amos. "Toughness enhancement of poly(ethylene terephthalate) with chemically modified ultra high molecular weight polyethylene." Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/13881.

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The present work was concentrated on exploring and developing a toughening material system to be used in engineering products made of high crystalline PET [poly(ethylene terephthalate)]. The work addressed some fundamental objectives in the technology. of crystallised PET (CPET) related to toughness and thermoforming. PET is widely used in fibres and oriented films but is also an attractive material for moulded products, owing to its high melting point and solvent resistance. Crystalline PET, however, is brittle and susceptible to hydrolytic degradation through water absorption. The polymeric toughening system was based on suitably modified UHMWPE (ultra high molecular weight polyethylene) a crystalline polymer with very high fracture toughness under plane strain conditions, low water absorption, but with a relatively low melting point. Being a thermoplastic it has a modulus about 1,000 times higher than the equivalent hydrocarbon elastomer usually used to toughen PET and polyamides. Hence, deterioration of strength and stiffness is minimized. Blending PET with UHMWPE produces coarse microstructures and poor mechanical properties due to lack of compatibility of the two polymers. Compatibility is expected to be improved by reducing the interfacial tension and increasing the adhesion between the two phases; the first will reduce the size of the dispersed phase, while the latter would improve the mechanical properties. Compatibilisation of a pair of immiscible polymers, like in blend of PET with UHMWPE, can be achieved by incorporation of reactive units along the main chains of the UHMWPE, which are capable of strong interactions with the matrix component (PET). The methods used in this investigation involved smface grafting and irradiation treatment to produce chemically active groups on the UHMWPE polymer chain to achieve the required level of interfacial adhesion assisting the agglomerate particle breakdown into small size and to develop strong bonding to the PET when the two polymers are blended in a high shear mixing. The results obtained with several modified UHMWPE powders incorporated into PET by melt mixing showed a clear formation of small primary particles of UHMWPE strongly bonded to the matrix, thereby achieving a vast improvement in toughness while preserving other important fundamental properties related to both the end product and the material processing.

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46

Swan, Michael David. "Morphological study of the shrinkage mechanisms in rapidly quenched polyethylene terephthalate melt-blown microfibres." Thesis, London Metropolitan University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341732.

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47

ARAO, MIEKA. "EVALUATION OF THE MECHANICAL BEHAVIOR OF ASPHALT MIXTURES WITH CRUSHED POLYETHYLENE TEREPHTHALATE (PET) INSERTION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2016. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=28076@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
A presente pesquisa tem como objetivo avaliar o comportamento de misturas asfálticas do tipo CBUQ (Concreto Betuminoso Usinado a Quente) adicionadas com garrafas PET (Polietileno Tereftalato) trituradas em diferentes granulometrias e teores. O filer convencional (pó de pedra) utilizado em misturas asfálticas foi substituído pelo pó proveniente da moagem das garrafas PET, já que o seu elevado ponto de fusão permite a utilização como agregado na mistura. Portanto, foi utilizado o material triturado nos diâmetros 10 mm e 2 mm, nos teores de 0,5 porcento e 1,0 porcento adicionadas ao CBUQ e, também, a substituição de 2,5 porcento do pó de pedra por pó de PET, juntamente com a adição de 0,5 porcento de PET triturado no diâmetro de 10 mm. A partir dos ensaios de caracterização dos agregados (granulometria, durabilidade, densidade, massa específica e abrasão Los Angeles) e do ligante asfáltico CAP 30/45 (densidade específica, penetração, ponto de amolecimento, ductilidade, solubilidade em tricloroetileno e envelhecimento em estufa de filme rotativo), foram feitas as dosagens das misturas asfálticas, pelo método Marshall, e a confecção de corpos de prova, o que possibilitou a realização dos ensaios mecânicos de estabilidade e fluência Marshall, resistência à tração, módulo de resiliência e de vida de fadiga. A inserção de PET triturado às misturas de CBUQ foi satisfatória, sendo os resultados dependentes dos teores e das granulometrias das partículas de PET utilizados. Observa-se que o incremento nos parâmetros de resistência e na vida útil das misturas estudadas foi mais efetivo para o CBUQ com 0,5 porcento de PET triturado em 10 mm e com a substituição de 2,5 porcento do filer por pó de PET, na sua composição granulométrica. Portanto, o uso de resíduos de garrafas PET para o melhoramento de misturas asfálticas pode minimizar os problemas atuais disposição do resíduo, contribuir com a redução do consumo de recursos naturais e dar um uso nobre para este material.
This research aims to evaluate the behavior of HMA mixtures (hot mix asphalt concrete) added with PET (Polyethylene Terephthalate) bottles pounded into different particle sizes and concentrations in the mixture. The usual filler (stone dust) was replaced by the powder from the milling of PET bottles, since its high melting point allows the use as an aggregate in the mix. Thus, it was used the material in diameters of 10 mm and 2 mm, in concentrations of 0.5 percent and 1.0 percent added in the HMA and, also, the replacement of 2.5 percent of the stone powder for the PET powder with addition of 0.5 percent triturated with diameter of 10 mm. From the characterization tests of aggregates (particle sizes, durability, density, Los Angeles abrasion) and asphalt (specific density, penetration, softening point, ductility, solubility in trichloroethylene, RTFOT – rolling thin film oven test), it was made the calculations of the dosage by the Marshall method, production of specimens, which enabled the realization of mechanical tests of Marshall Stability and Flow, Tensile Strength, Resilient Modulus and Fatigue. The insertion of triturated PET was satisfactory, being dependent on the results of the percentages and particle sizes of the PET used. It was observed that the increase in the strength parameters and the useful life of the mixtures studied is more effective for the HMA with 0.5 percent PET of 10 mm diameter and the substitution of 2.5 percent of the filler for PET powder in its granulometric compositions. Therefore, the use of PET bottle waste to the improvement of asphalt mixtures can minimize the current problems of waste disposal, contribute to reduce the consumption of natural resources and make a noble use for this material.

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48

Wieckiewicz, Mieszko, Eric Wolf, Gert Richter, Heike Meissner, and Klaus Boening. "New Concept of Polymethyl Methacrylate (PMMA) and Polyethylene Terephthalate (PET) Surface Coating by Chitosan." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-215855.

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Chitosan is known for its hemostatic and antimicrobial properties and might be useful for temporary coating of removable dentures or intraoral splints to control bleeding after oral surgery or as a supportive treatment in denture stomatitis. This study investigated a new method to adhere chitosan to polymethyl methacrylate (PMMA) and polyethylene terephthalate (PET). There were 70 cylindrical specimens made from PMMA and 70 from PET (13 mm diameter, 6 mm thickness). The materials with ten specimens each were sandblasted at 2.8 or 4.0 bar with aluminum oxide 110 μm or/and aluminum oxide coated with silica. After sandblasting, all specimens were coated with a 2% or 4% acetic chitosan solution with a thickness of 1 mm. Then the specimens were dried for 120 min at 45 °C. The precipitated chitosan was neutralized with 1 mol NaOH. After neutralization, all specimens underwent abrasion tests using the tooth-brushing simulator with soft brushes (load 2N, 2 cycles/s, 32 °C, 3000 and 30,000 cycles). After each run, the specimen surfaces were analyzed for areas of remaining chitosan by digital planimetry under a light microscope. The best chitosan adhesion was found after sandblasting with aluminum oxide coated with silica (U-Test, p < 0.05) in both the PMMA and the PET groups. Hence, with relatively simple technology, a reliable bond of chitosan to PMMA and PET could be achieved.

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49

Onggar, Toty, Shayed Mohammad Abu, Rolf-Dieter Hund, and Chokri Cherif. "Silvering of three-dimensional polyethylene terephthalate textile material by means of wet-chemical processes." Sage, 2015. https://tud.qucosa.de/id/qucosa%3A35399.

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The aim of this research is to develop a wet-chemical silvering method for a three-dimensional (3D) textile material made of polyethylene terephthalate (PET) to prevent and eliminate biological contaminants in drinking water and other liquid-containing systems. Three-dimensional textile fabrics are particularly well-suited as silvered disinfection materials in water systems, because they have 3D structures, pressure-elastic textile design, and provide large contact areas. Furthermore, water can easily be passed through the structure. The developed wet-chemical procedures are based on aminosilane, which consists of at least two amine groups and is well-suited to form a silver diamine complex. The silvered textile material was coated with cationic silver. After the chemical reduction, the cationic silver turns into metallic silver on the surface of PET spacer fabrics. The surface morphology of silver-coated spacer fabrics was analyzed and the uniform silver layer on the PET fiber surface was found. X-ray diffraction and energy-dispersive X-ray spectroscopy analysis spectrums showed that the silver was immobilized on the PET fiber surface. The layer thickness and the silver amount were also determined. The silvered spacer fabrics can be used in sealing and/or cooling water systems; therefore, the silver ion release in water was analyzed. Furthermore, textile physical tests for the measurement of breaking force and elongation were carried out. No significant change in breaking force and elongation was observed after silvering of PET spacer fabric.

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50

Wieckiewicz, Mieszko, Eric Wolf, Gert Richter, Heike Meissner, and Klaus Boening. "New Concept of Polymethyl Methacrylate (PMMA) and Polyethylene Terephthalate (PET) Surface Coating by Chitosan." Molecular Diversity Preservation International (MDPI), 2016. https://tud.qucosa.de/id/qucosa%3A30051.

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Chitosan is known for its hemostatic and antimicrobial properties and might be useful for temporary coating of removable dentures or intraoral splints to control bleeding after oral surgery or as a supportive treatment in denture stomatitis. This study investigated a new method to adhere chitosan to polymethyl methacrylate (PMMA) and polyethylene terephthalate (PET). There were 70 cylindrical specimens made from PMMA and 70 from PET (13 mm diameter, 6 mm thickness). The materials with ten specimens each were sandblasted at 2.8 or 4.0 bar with aluminum oxide 110 μm or/and aluminum oxide coated with silica. After sandblasting, all specimens were coated with a 2% or 4% acetic chitosan solution with a thickness of 1 mm. Then the specimens were dried for 120 min at 45 °C. The precipitated chitosan was neutralized with 1 mol NaOH. After neutralization, all specimens underwent abrasion tests using the tooth-brushing simulator with soft brushes (load 2N, 2 cycles/s, 32 °C, 3000 and 30,000 cycles). After each run, the specimen surfaces were analyzed for areas of remaining chitosan by digital planimetry under a light microscope. The best chitosan adhesion was found after sandblasting with aluminum oxide coated with silica (U-Test, p < 0.05) in both the PMMA and the PET groups. Hence, with relatively simple technology, a reliable bond of chitosan to PMMA and PET could be achieved.

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Dissertations / Theses on the topic 'Polyethylene terephthalate'

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