L’objectif de cette thèse est de contribuer à la compréhension et à la modélisation de la cristallisation induite. Le phénomène est caractérisé pour deux matériaux : le PET et le caoutchouc naturel réticulé. Les conditions favorables au phénomène, de type caoutchoutique sont déterminées par analyses calorimétriques et spectroscopiques. La microstructure qui se développe au cours de la déformation est observée par diffraction des rayons X.Le PET est déformé en traction uni- et biaxiale. Une partie des étirages est suivie d’une relaxation des contraintes, une autre est suivie d’une trempe rapide. Il ressort de l’étude que l’étirage du PET dans ces conditions n’aboutit pas à l’obtention d’un cristal PET avec toutes les périodicités qui lui sont propres.Le caoutchouc naturel est déformé en traction uniaxiale et en cisaillement précédé d’un étirage uniaxial. En cisaillement, la phase cristalline obtenue au cours du pré-étirage ou du cisaillement tourne et tend à s’orienter comme les directions des déformations principales mais avec un retard angulaire. L’extension principale est utilisée pour étudier la phase cristalline obtenue pour les différents modes de sollicitation.Un modèle de comportement visco-hyperélastique, décrit dans le cadre de la thermodynamique des processus irréversibles, est étendu afin de reproduire le durcissement mécanique lié au développement d’une phase organisée/cristalline. Le modèle permet de reproduire les différents comportements mécaniques observés expérimentalement. / The present PhD thesis aims at a better understanding and modeling of strain-induced-crystallization. The phenomenon is characterized for two polymers: PET and crosslinked natural rubber. Strain conditions leading to strain-induced-crystallization are determined by thermal and dynamic mechanical analysis. The developing microstructure is observed by X-ray scattering.The PET is stretched in uni- and biaxial tension. A part of samples is rapidly quenched after stretching and another is submitted to a stress relaxation after stretching. The studies demonstrate that the stretching of PET does not enable the formation of a complete PET crystal with all its own families of planes.The crosslinked natural rubber is stretched in uniaxial tension and in shear preceded by uniaxial stretching. In shear, the crystalline phase, appeared during the pre-stretching or during the shear rotates and has a tendency to orient as the directions of the principal strains. The principal elongation is used to compare the crystallization under the different stresses.A constitutive modeling for visco-hyperelastic behaviors, in a complete thermodynamics framework of irreversible processes, is extended in order to reproduce le mechanical hardening related to the development of an organized/crystalline phase. The modeling successes in reproducing the experimental behaviors in uploading/unloading for various strain conditions.

Made available in DSpace on 2015-04-22T22:02:02Z (GMT). No. of bitstreams: 1 Dissertacao Vera Lucia Imbiriba Bentes.pdf: 2492256 bytes, checksum: 6177030a4e14eea635a818dbbb2b0e91 (MD5) Previous issue date: 2008-11-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The growing use and application of plastic materials have raised the index of residues of these materials in the great cities, mainly poli(ethylene tereftalate) (PET). Amongst the recycling techniques proposals to minimize the accumulation of these polymeric residues, the chemical recycling, has intensified the interest, on the part of the scientific community, a time that products of a high aggregate value can be achieved, that they can be used in new industrial processes. Of this form, the present work had as objective, to investigate the solubility of the PET postconsumer in different chemical agents, to promote the depolymerization chemical of the PET by hydrolysis basic and to carry preliminary study of the degradation of monomers post-hydrolysis through heterogeneous Fenton reaction using pure and Co- and Mn-doped magnetites catalysts, as source of Fe2+ in H2O2 having as molecule of reference for the study, the methylene blue (MB). The hydrolysis reaction was carried in reflux system under temperature of 110 oC for three hours using NaOH 7.5 mol L-1 as catalytic and the gotten products had been characterized by spectroscopic method in the region of the IV. The reactions of heterogeneous Fenton had been monitored by UV-visible measurements. Between the gotten results, it could be verified (i) PET solubility in phenol concentrated solution of about 40 oC; (ii) the chemical recycling of the PET presented yield of 99.72 % with recovery of monomers terephthalic acid (AT) and ethylene glycol (EG) monomers which were characterized by IV; (iii) the study of degradation of the methylene blue (MB) 20 mg L-1 was monitored by UV-visible measurements in λmax = 663 nm thus the kinetic model that better described the process was of the pseudo first-order, disclosing bigger capacity of degradation for the doped magnetite catalysers with Co and Mn, respectively; (iv) degradation of AT, was observed in λmax = 283 nm and had a similar behavior to the reference molecule; (v) the loss of the organic load of the solution afterhydrolysis of the PET was bottle was analyzed qualitatively by comparison of the spectrums obtained by FT-IV/ATR before and after of the heterogeneous Fenton reaction. Thus the results gotten in this work are considered satisfactory and promising for news studies future. / O crescente uso e aplicação de materiais plásticos tem elevado os índices de resíduos desses materiais nos lixões das grandes cidades, principalmente, o poli(tereftalato de etileno) (PET). Dentre as técnicas de reciclagem propostas para minimizar o acúmulo desses resíduos poliméricos, a reciclagem química, tem despertado maior interesse por parte da comunidade científica, uma vez que se podem obter produtos de elevado valor agregado, que podem ser utilizados em novos processos industriais. Dessa forma, o presente trabalho teve como objetivos, investigar a solubilidade do PET pós-consumo em diferentes agentes químicos, promover a despolimerização química do PET via hidrólise básica e realizar estudo preliminar da degradação dos monômeros pós-hidrólise através de reação de Fenton heterogênea utilizando catalisadores de magnetitas pura e dopadas com Co e Mn, como fonte de Fe2+em presença de H2O2, tendo como molécula de referência para o estudo, o corante azul de metileno (MB). A reação de hidrólise foi conduzida em sistema de refluxo sob temperatura de 110oC por três horas, utilizando NaOH 7,5 molL-1 como catalisador da reação e os produtos finais foram caracterizados por método espectroscópico na região de absorção do IV. As reações de Fenton heterogênea foram monitoradas através de medidas espectrofotométricas na região do UV-visível. Entre os resultados obtidos, pôde-se verificar (i) a solubilidade do PET em solução concentrada de fenol ∼ 40 oC; (ii) a reciclagem química do PET apresentou rendimento de 99,72 % com recuperação dos monômeros do ácido tereftálico (AT) e de etileno glicol (EG) que foram caracterizados por IV; (iii) o estudo da degradação da molécula de referência, MB 20 mg L -1, foi monitorado em λ = 663 nm, de maneira que o modelo cinético que melhor descreveu o processo foi o de pseudo primeira-ordem, revelando maior capacidade de degradação para os catalisadores de magnetitas dopadas com Co e Mn, respectivamente; (iv) a degradação do AT, foi observado em λ = 283 nm e teve comportamento semelhante ao da molécula de referência; (v) a perda de carga orgânica da solução pós-hidrólise do PET foi feita qualitativamente por comparação dos espectros IV/ATR das amostras de solução pós-hidrólise antes e depois de submetida á reação de Fenton. De maneira geral os resultados obtidos neste trabalho são considerados satisfatórios e promissores para outros futuros estudos.

L'évolution de la microstructure du poly(éthylène terephthalate) (polymère thermoplastique amorphe et cristallisable) a été étudiée lors de diverses sollicitations mécaniques (mono-étirage, bi-étirage et soufflage en surface libre). Le matériau a été sollicité entre les températures de transition vitreuse et de cristallisation froide (i.e. 90 °C et 115 °C). Différents traitements thermiques (recuit ou trempe) ont été appliqués après déformation. L'évolution de la texture et de la morphologie cristalline a été étudiée par différentes techniques de diffraction des rayons X (WAXS et SAXS). L'évolution de la phase amorphe a, quant à elle, été étudiée par analyse mécanique dynamique et thermique (DMTA).Quelque soit la nature des échantillons (films, éprouvettes épaisses ou préformes), des sollicitations et des conditions expérimentales (vitesses et températures), il appairait clair que la cristallisation sous déformation du PET ne conduit pas à une microstructure cristalline parfaite si elle est ponctuée par une trempe, excepté pour des taux d'étirage élevés. La microstructure observée en fin d'étirage est donc aussi marquée par l'étape de refroidissement. Le durcissement structural est lié aux étapes initiales de la cristallisation. La phase amorphe est pour sa part fortement contrainte par la sollicitation. Pour preuve, sa plus grande aptitude à la cristallisation et les évolutions de sa température de transition alpha qui augmente. Les essais de soufflage libre ont notamment démontré combien les bouteilles sont hétérogènes tant en terme de morphologie microstructurale qu'en terme d'orientation locale des chaînes polymères. Cette hétérogénéité se manifeste aussi bien le long des bouteilles qu'au sein de leur épaisseur, rendant difficile la corrélation entre propriétés microstructurale et mécanique induites. L'étude comparative des corps creux soufflés sur prototype et souffleuse industrielle a permis d'évaluer l'influence du moule. Dans des conditions équivalentes, le moule contraint de toute évidence les déformations du matériau et peut donc avoir une incidence non négligeable sur les microstructures et propriétés induites finales.

The properties of materials, especially of solids, can be attributed mainly to the phenomena occurring at the surface. Surface engineering deals with altering the surface properties of materials to realize useful functionalities like wear and corrosion resistance, biocompatibility, hardening etc. Among the various methods adopted, plasma surface modification stands out, because of the inherent dry processing nature and little amount of left over chemicals. In conventional plasma systems, the process is carried out in a low pressure environment. This restricts its use in treating vacuum incompatible materials including tissues and bio-medical samples. Moreover, the batch processing nature and use of expensive vacuum pumps put a bottle-neck in the throughput of any production line. The subject matter of this thesis is about developing and optimizing an atmospheric pressure (760 torr) plasma system and to use it for surface modification of polymers. The experimental system developed, consists of two parallel electrodes facing each other, each of which is covered with a dielectric plate. A gap of 4mm exists between the dielectric surfaces, through which an axial flow of the working gas is maintained. When a high voltage is applied across the electrodes, the gas breaks down, creating plasma. The surface of the sample kept in this plasma, undergoes various phenomena, depending on the power applied, type of gas used and gas flow rate. To drive the plasma a high voltage power supply, which is able to generate 10 kV at 5.8 kHz, was developed in the laboratory. By varying the process parameters, the inherent filamentary nature of discharge can be converted to a diffuse uniform glow. The purity of plasma was studied and established by analyzing the optical emission from the plasma. After optimizing the system, it was used to modify the surface properties of polyester sheets. The wetting nature was altered using fluorocarbon and oxygen plasmas, realizing hydrophobic and hydrophilic surfaces. The contact angle of a water droplet made with the surface changed from 72° to 84° degree for hydrophobic and to 22° for hydrophilic surfaces respectively. Through this investigation, an insight to the procedure for developing an Atmospheric glow discharge system was developed. The details about system frame work, the power supply, electrical and optical characterization of the plasma, are well studied and recorded. The work establishes the various parameters to be varied to convert the filamentary discharge to a uniform glow. Purity of the plasma has been studied extensively and the system design and process values essential for maintaining the purity have been dealt with. Finally the plasma was put in use for surface modification of polymers, and the surface wetting nature alteration was studied and quantified.

Blends of poly butylene terephthalate (PBT) and polycarbonate (PC) form a very important class of commercial blends in numerous applications requiring materials with good chemical resistance, impact resistance even at low temperatures, and aesthetic and flow characteristics. PC and PBT are usually blended in a twin screw extruder (TSE). Product melt volume flow rate (MVR) is a property used to monitor product quality while blending the PC/PBT in a twin screw extruder. It is usually measured off line in a quality control laboratory using extrusion plastometer on samples collected discretely during the compounding operation. Typically a target value representing the desired value of the quality characteristics for an in-control process, along with upper and lower control limits are specified. As long as the MVR measurement is within the control limits, the sample is approved and the whole compounded blend is assumed to meet the specification. Otherwise, the blend is rejected. Because of infrequent discrete sampling, corrective actions are usually applied with delay, thus resulting in wasted material. It is important that the produced PC/PBT blend pellets have consistent properties. Variability and fault usually arise from three sources: human errors, feed material variability, and machine operation (i.e. steady state variation). Among these, the latter two are the major ones affecting product quality. The resulting variation in resin properties contributes to increased waste products, larger production cost and dissatisfied customers. Motivated by this, the objective of this project was to study the compounding operation of PC/PBT blend in a twin screw extruder and to develop a feasible methodology that can be applied on-line for monitoring properties of blends on industrial compounding operations employing available extruder input and output variables such as screw speed, material flow rate, die pressure and torque. To achieve this objective, a physics-based model for a twin screw extruder along with a MVR model were developed, examined and adapted for this study, and verified through designed experiments. This dynamic model for a TSE captures the important dynamics, and relates measurable process variables (screw speed, torque, feed rates, pressure etc.) to ones that are not being measured (material holdups and compositions at the partially and filled section along a TSE barrel). This model also provides product quality sensors or inferential estimation techniques for prediction of viscosity and accordingly MVR. The usefulness of the model for inferential MVR sensing and fault diagnosis was demonstrated on experiments performed on a 58 mm co-rotating twin-screw extruder for an industrial compounding operation at a SABIC Innovative Plastics plant involving polycarbonate – poly butylene terephthalate blends. The results showed that the model has the capability of identifying faults (i.e., process deviation from the nominal conditions) in polymer compounding operations with the twin screw extruder. For instance, the die pressure exhibited a change as a function of changes in raw materials and feed composition of PC and PBT. In the presence of deviations from nominal conditions, the die pressure parameters are updated. These die pressure model parameters were identified and updated using the recursive parameter estimation method. The recursive identification of the die pressure parameters was able to capture very well the effects of changes in raw material and/or composition on the die pressure. In addition, the developed MVR model showed a good ability in monitoring product MVR on-line and inferentially from output process variables such as die pressure which enables quick quality control to maintain products within specification limits and to minimize waste production.

In this work, the compounding of polycarbonate (PC) / poly-butylene terephthalate (PBT) blends was studied for the purpose of improving quality of products with reduced wastage and finally to satisfaction of end users. The effect of material rheological characteristics and processing conditions on compounding of PC /PBT was investigated through statistical experiments carried out on a 58 mm twin-screw extruder at SABIC Innovative Plastics Limited (formerly GE Plastics Limited) in Cobourg, Ontario. Melt Volume-Flow Rate (MVR) is the most commonly used property to monitor the quality of products of PC/PBT blends. The MVR was studied with different sampling times and correlations between product properties (melt flow) and processing conditions (screw speed, flow rates) were discussed. The rheological behavior of PC/PBT blends was investigated by dynamic and capillary rheometers. The effects of processing conditions (screw speed, feed rate) on viscosity were measured and it was found that the Cox-Merz rule is not valid for PC/PBT blends. The change of morphology of PC/PBT blends was observed under a scanning electron microscope (SEM) by using different types of samples. Those samples were (i) PC/PBT blends pellets, (ii) PC/PBT blend samples, but collected after completing the rheological tests in the parallel plate rheometer, and (iii) PC/PBT blend samples, but collected after completing the rheological tests in the capillary rheometer. There was evidence that the samples collected after completing the tests in the parallel and capillary rheometer might be degraded due to temperature and time.

Blends of poly butylene terephthalate (PBT) and polycarbonate (PC) form a very important class of commercial blends in numerous applications requiring materials with good chemical resistance, impact resistance even at low temperatures, and aesthetic and flow characteristics. PC and PBT are usually blended in a twin screw extruder (TSE). Product melt volume flow rate (MVR) is a property used to monitor product quality while blending the PC/PBT in a twin screw extruder. It is usually measured off line in a quality control laboratory using extrusion plastometer on samples collected discretely during the compounding operation. Typically a target value representing the desired value of the quality characteristics for an in-control process, along with upper and lower control limits are specified. As long as the MVR measurement is within the control limits, the sample is approved and the whole compounded blend is assumed to meet the specification. Otherwise, the blend is rejected. Because of infrequent discrete sampling, corrective actions are usually applied with delay, thus resulting in wasted material. It is important that the produced PC/PBT blend pellets have consistent properties. Variability and fault usually arise from three sources: human errors, feed material variability, and machine operation (i.e. steady state variation). Among these, the latter two are the major ones affecting product quality. The resulting variation in resin properties contributes to increased waste products, larger production cost and dissatisfied customers. Motivated by this, the objective of this project was to study the compounding operation of PC/PBT blend in a twin screw extruder and to develop a feasible methodology that can be applied on-line for monitoring properties of blends on industrial compounding operations employing available extruder input and output variables such as screw speed, material flow rate, die pressure and torque. To achieve this objective, a physics-based model for a twin screw extruder along with a MVR model were developed, examined and adapted for this study, and verified through designed experiments. This dynamic model for a TSE captures the important dynamics, and relates measurable process variables (screw speed, torque, feed rates, pressure etc.) to ones that are not being measured (material holdups and compositions at the partially and filled section along a TSE barrel). This model also provides product quality sensors or inferential estimation techniques for prediction of viscosity and accordingly MVR. The usefulness of the model for inferential MVR sensing and fault diagnosis was demonstrated on experiments performed on a 58 mm co-rotating twin-screw extruder for an industrial compounding operation at a SABIC Innovative Plastics plant involving polycarbonate – poly butylene terephthalate blends. The results showed that the model has the capability of identifying faults (i.e., process deviation from the nominal conditions) in polymer compounding operations with the twin screw extruder. For instance, the die pressure exhibited a change as a function of changes in raw materials and feed composition of PC and PBT. In the presence of deviations from nominal conditions, the die pressure parameters are updated. These die pressure model parameters were identified and updated using the recursive parameter estimation method. The recursive identification of the die pressure parameters was able to capture very well the effects of changes in raw material and/or composition on the die pressure. In addition, the developed MVR model showed a good ability in monitoring product MVR on-line and inferentially from output process variables such as die pressure which enables quick quality control to maintain products within specification limits and to minimize waste production.

In this work, the compounding of polycarbonate (PC) / poly-butylene terephthalate (PBT) blends was studied for the purpose of improving quality of products with reduced wastage and finally to satisfaction of end users. The effect of material rheological characteristics and processing conditions on compounding of PC /PBT was investigated through statistical experiments carried out on a 58 mm twin-screw extruder at SABIC Innovative Plastics Limited (formerly GE Plastics Limited) in Cobourg, Ontario. Melt Volume-Flow Rate (MVR) is the most commonly used property to monitor the quality of products of PC/PBT blends. The MVR was studied with different sampling times and correlations between product properties (melt flow) and processing conditions (screw speed, flow rates) were discussed. The rheological behavior of PC/PBT blends was investigated by dynamic and capillary rheometers. The effects of processing conditions (screw speed, feed rate) on viscosity were measured and it was found that the Cox-Merz rule is not valid for PC/PBT blends. The change of morphology of PC/PBT blends was observed under a scanning electron microscope (SEM) by using different types of samples. Those samples were (i) PC/PBT blends pellets, (ii) PC/PBT blend samples, but collected after completing the rheological tests in the parallel plate rheometer, and (iii) PC/PBT blend samples, but collected after completing the rheological tests in the capillary rheometer. There was evidence that the samples collected after completing the tests in the parallel and capillary rheometer might be degraded due to temperature and time.

Made available in DSpace on 2014-12-17T14:07:01Z (GMT). No. of bitstreams: 1 RosanneLFD_DISSERT.pdf: 2030152 bytes, checksum: fac9b7e6c23b892eb3fd86ea5b5f43bc (MD5) Previous issue date: 2011-11-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Among the options for plastics modification more convenient, both from a technical-scientific and economic, is the development of polymer blends by processing in the molten state. This work was divide into two stages, with the aim to study the phase morphology of binary blend PMMA / PET blend and this compatibilized by the addition of the poly(methyl methacrylate-co-glycidyl methacrylate-co-ethyl acrylate) copolymer (MMA-GMA-EA). In the first stage is analyzed the morphology of the blend at a preliminary stage where we used the bottle-grade PET in a Haake torque rheometer and the effect of compatibilizer in this blend was evaluated. In the second stage the blend was processed using the recycled PET in a single screw extruder and subsequently injection molding in the shape of specimens for mechanical tests. In both stages we used a transmission electron microscopy (TEM) to observe the morphologies of the samples and an image analyzer to characterize them. In the second stage, as well as analysis by TEM, tensile test, scanning electron microscopy (SEM) and atomic force microscopy (AFM) was performed to correlate the morphology with the mechanical properties. The samples used in morphological analyzes were sliced by cryo-ultramicrotomy technique for the analysis by TEM and the analysis by SEM and AFM, we used the flat face of the block after cut cryogenic. It was found that the size of the dispersed phase decreased with the addition of MMA-GMA-EA in blends prepared in a Haake. In the tensile test, the values of maximum tensile strength and modulus of elasticity is maintained in a range between the value of pure PMMA the pure PET, while the elongation at break was influenced by the composition by weight of the PMMA mixture. The coupling agent corroborated the results presented in the blend PMMA / PETrec / MMA-GMA-EA (80/15/5 %w/w), obtained by TEM, AFM and SEM. It was concluded that the techniques used had a good morphologic correlation, and can be confirmed for final analysis of the morphological characteristics of the blends PMMA / PET / Entre as op??es de modifica??o de pl?sticos mais convenientes, tanto do ponto de vista t?cnico-cient?fico como econ?mico, encontra-se o desenvolvimento de blendas polim?ricas por meio de processamento no estado fundido. Este trabalho foi dividido em dois est?gios, tendo como objetivo o estudo da morfologia de fases da blenda bin?ria PMMA/PET e desta compatibilizada pela adi??o do copol?mero poli(metacrilato de metila-co-metacrilato de glicidila-co-acrilato de etila) (MMA-GMA-EA). No primeiro est?gio analisou-se a morfologia da blenda e avaliou-se o efeito do compatibilizante, onde foi usado o PET grau garrafa em um re?metro de torque Haake. J? no segundo est?gio a blenda foi processada empregando desta vez o PET reciclado em uma extrusora monorosca, e posteriormente, moldada por inje??o em forma de corpos de prova para ensaios mec?nicos. Nos dois est?gios utilizou-se a microscopia eletr?nica de transmiss?o (MET) para observar as morfologias das amostras e um analisador de imagens para caracteriz?-las. No segundo estagio, al?m da an?lise por MET, foi realizado ensaio de tra??o, microscopia eletr?nica de varredura (MEV) e microscopia de for?a at?mica (MFA), buscando correlacionar a morfologia com as propriedades mec?nicas. As amostras utilizadas nas an?lises morfol?gicas foram fatiadas por meio da t?cnica crio-ultramicrotomia para na an?lise por MET e para as an?lises por MEV e por MFA, foi utilizada a face plana do tarugo p?s-corte criog?nico. Verificou-se que o tamanho da fase dispersa diminui em fun??o da adi??o do copol?mero MMA-GMA-EA nas blendas preparadas no re?metro Haake. No ensaio de tra??o, os valores de resist?ncia m?xima sob tra??o e m?dulo de elasticidade mantiveram-se em um patamar entre o valor de PMMA puro e do PET puro, enquanto que o alongamento na ruptura mostrou-se influenciada pela composi??o em massa de PMMA na mistura. O agente compatibilizante corroborou nos resultados apresentados da blenda PMMA/PETrec /MMA-MGA-EA (80/15/5), obtidos por MET, MFA e MEV. Concluiu-se que as t?cnicas morfol?gicas utilizadas apresentaram uma boa correla??o e corroboraram para an?lise final das caracter?sticas morfol?gicas das blendas PMMA/PET

Made available in DSpace on 2014-12-17T14:07:12Z (GMT). No. of bitstreams: 1 JucikleciaSR_DISSERT.pdf: 18878091 bytes, checksum: 13af0d90d6b4b0980975e46b7393cd8c (MD5) Previous issue date: 2013-08-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work studied the immiscible blend of elastomeric poly(methyl methacrylate) (PMMA) with poly(ethylene terephthalate) (PET) bottle grade with and without the use of compatibilizer agent, poly(methyl methacrylate-co-glycidyl methacrylate - co-ethyl acrylate) (MGE). The characterizations of torque rheometry, melt flow index measurement (MFI), measuring the density and the degree of cristallinity by pycnometry, tensile testing, method of work essential fracture (EWF), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were performed in pure polymer and blends PMMA/PET. The rheological results showed evidence of signs of chemical reaction between the epoxy group MGE with the end groups of the PET chains and also to the elastomeric phase of PMMA. The increase in the concentration of PET reduced torque and adding MGE increased the torque of the blend of PMMA/PET. The results of the MFI also show that elastomeric PMMA showed lower flow and thus higher viscosity than PET. In the results of picnometry observed that increasing the percentage of PET resulted in an increase in density and degree crystallinity of the blends PMMA/PET. The tensile test showed that increasing the percentage of PET resulted in an increase in ultimate strength and elastic modulus and decrease in elongation at break. However, in the phase inversion, where the blend showed evidence of a co-continuous morphology and also, with 30% PET dispersed phase and compatibilized with 5% MGE, there were significant results elongation at break compared to elastomeric PMMA. The applicability of the method of essential work of fracture was shown to be possible for most formulations. And it was observed that with increasing elastomeric PMMA in the formulations of the blends there was an improvement in specific amounts of essential work of fracture (We) and a decrease in the values of specific non-essential work of fracture (βWp) / Neste trabalho ? estudada a blenda imisc?vel poli(metacrilato de metila) (PMMA) elastom?rico com poli(tereftalato de etileno) (PET) grau garrafa com e sem o uso do agente compatibilizante, poli(metacrilato de metila-co-metacrilato de glicidilaco- acrilato de etila) (MGE). As caracteriza??es de reometria de torque, medida de ?ndice de fluidez (MFI), determina??o da densidade e do grau de cristalinidade por picnometria, ensaio de tra??o uniaxial, m?todo do trabalho essencial fratura (EWF), microscopia eletr?nica de varredura (MEV) e microscopia eletr?nica de transmiss?o (MET), foram realizadas nos pol?meros puros e nas blendas PMMA/PET. Os resultados reol?gicos apresentaram ind?cios de rea??o qu?mica entre o grupo ep?xi do MGE com os grupos finais de cadeias do PET e, tamb?m, com a fase elastom?rica do PMMA. O aumento na concentra??o de PET reduziu o torque e a adi??o do MGE aumentou o torque da blenda PMMA/PET. Os resultados de MFI mostraram tamb?m que, o PMMA elastom?rico apresentou menor fluidez e, consequentemente, maior viscosidade que o PET. Nos resultados de picnometria observou-se que, o aumento da porcentagem de PET proporcionou um aumento na densidade e no grau de cristalinidade das blendas PMMA/PET. Os ensaios de tra??o mostraram que, o aumento da porcentagem de PET proporcionou um aumento na resist?ncia m?xima e no m?dulo de elasticidade e uma diminui??o no alongamento na ruptura. Entretanto, na invers?o de fase, onde a blenda apresentou ind?cios de uma morfologia cocont?nua e tamb?m, com 30% de fase dispersa PET e compatibilizada com 5% de MGE, verificaram-se resultados expressivos de alongamento na ruptura em rela??o ao PMMA elastom?rico. A aplicabilidade do m?todo do trabalho essencial de fratura mostrou-se poss?vel para a maioria das formula??es. Observou-se ainda que, com o aumento do PMMA elastom?rico nas formula??es das blendas, ocorreu uma melhoria nos valores do trabalho essencial espec?fico de fratura (We) e uma redu??o nos valores do trabalho n?o essencial espec?fico de fratura (βWp)