Orientador: Prof. Dr. Carlos Henrique Scuracchio / Tese (doutorado0 - Universidade Federal do ABC, Programa de Pós-Graduação em Nanociências e Materiais Avançados, 2014. / O objetivo principal deste trabalho foi a produção de blendas dinamicamente revulcanizadas contendo polietileno de alta densidade (HDPE) e ground tire rubber (GTR) desvulcanizada via micro-ondas. Ele vem de encontro a um grande problema mundial que é a disposição de resíduos de elastômeros vulcanizados, especialmente de pneus, que trazem consigo graves problemas ambientais e de saúde pública, já que estes materiais necessitam de longos períodos de tempo para que se degradem naturalmente devido à sua estrutura de ligações cruzadas, presença de estabilizantes e outros aditivos em sua formulação. Uma utilização da GTR que vem sendo amplamente estudada por pesquisadores é em blendas poliméricas, tendo por uma das fases um polímero termoplástico. Neste contexto, o papel da desvulcanização dos elastômeros é aumentar a interação entre o material virgem e o reciclado, diminuindo a degradação das propriedades do produto acabado com a sua incorporação e possibilitando o aumento da quantidade de borracha reciclada no composto de borracha reciclada/termoplástico. A desvulcanização torna o elastômero desvulcanizado um material fluido, possibilitando um melhor controle do tamanho de partículas durante o processo de mistura da blenda pelos processos de quebra na aplicação de altas taxas de cisalhamento. Além disso, ao tornar-se um material fluido, é possível a incorporação de uma quantidade maior de borracha ao termoplástico sem grande prejuízo à sua processabilidade. No entanto, a literatura não dispõe de trabalhos nos quais o estudo da evolução da morfologia de blendas dinamicamente revulcanizadas contendo GTR desvulcanizada por micro-ondas é realizado, e esse estudo é uma das principais etapas deste trabalho. Do mesmo modo, não são encontrados trabalhos sobre blendas contendo GTR desvulcanizada analisando os efeitos da adição de argilas de diferentes formatos (lamelar e tubular) em suas propriedades finais, especialmente nas propriedades reológicas, o que também se propõe o presente trabalho. Em suma, este trabalho tem como objetivos propor uma possível solução para o problema de descarte de resíduos sólidos através da produção de uma blenda dinamicamente revulcanizada contendo HDPE e GTR desvulcanizada via micro-ondas, bem como diminuir algumas lacunas observadas atualmente na literatura com os resultados do estudo da evolução da morfologia de blendas dinamicamente revulcanizadas contendo GTR desvulcanizada e o efeito da adição de diferentes argilas nesse sistema. / The main objective of this work was the production of dynamically revulcanized blends containing HDPE and GTR devulcanized by microwaves. It comes against a big global problem which is the waste disposal of vulcanized elastomers, especially tires, which bring with them serious environmental and public health problems, since these materials require long periods of time to degrade naturally due to its structure of cross-linkings, and the presence of stabilizers and other additives in its formulation. A way of using the GTR that has been widely studied by researchers is as polymer blends where one of the phases is a thermoplastic polymer. In this context, the role of elastomers devulcanization is to increase the interaction between virgin and recycled material, reducing the degradation of properties of the finished product with its incorporation and making it possible the increase of the recycled rubber amount in the compound recycled rubber/thermoplastic. The devulcanization transformes devulcanized elastomer into a fluid material, allowing a better control of the particle size during the mixing process of the blend by breaking processes in the application of high shear rates. In addition, by becoming a fluid material, it is possible the incorporation of a higher amount of elastomer to the thermoplastic without great damage to its processability. However, the literature does not have works in which the study of the morphology evolution of dynamically revulcanized blends containing GTR devulcanized by microwaves is performed, and this study is one of the main stages of the present work. Likewise, it is not found works on blends containing devulcanized GTR analyzing the effects of addition of clays from different shapes (lamellar and tubular) on their final properties, especially on rheological properties, which also sets out the present work. Summarizing, this work aims to propose a possible solution to the problem of solid waste disposing by producing a dynamically revulcanized blend containing HDPE and GTR devulcanized by microwaves, as well as decrease some gaps observed currently in the literature with the study of the morphology evolution of dynamically revulcanized blends containing devulcanized GTR and the effect of addition of different clays on these systems.

Ces dernières années, la recherche de solutions au problème de l'élimination de déchets polymères, notamment les déchets issus de pneumatiques qui posent de graves problèmes environnementaux, connait un développement croissant. Dans ce contexte, ce projet de recherche a pour objectif de contribuer au développement et à la promotion de solutions innovantes qui font appel aux connaissances développées dans les domaines des nanotechnologies, de la science et l’ingénierie des matériaux nouveaux et du génie des procédés et des produits. Il s’agit plus particulièrement de d’étudier la possibilité de valoriser les déchets issus de pneumatiques en les utilisant comme matière première (en tant que agents de renfort ou agents de modification de la résistance aux chocs) pour l'élaboration de matériaux nanostructurés. Ce travail met l'accent sur l'étude des mélanges de polyéthylène haute densité (PEHD) contenant des particules d’argile (dispersées à l'échelle du nanomètre) et des déchets de caoutchouc issus de pneumatiques usagés (ou Ground Rubber Tire ou GRT). Il est attendu que ce matériau présente des propriétés typiques des mélanges de polymères appelés Vulcanisats Thermoplastiques (TPVs), résultant de la vulcanisation dynamique de la phase de caoutchouc pendant le traitement à l'état de fondu (extrusion). Dans le système étudié, la matrice est le PEHD et la phase dispersée de la poudrette de pneu, préalablement dévulcanisée par micro-ondes. L'argile dispersée dans la phase de la matrice, agit comme un agent compatibilisant entre les phases du mélange et comme agent de renforcement, apportant une amélioration des propriétés mécaniques des matériaux préparés. La caractérisation des mélanges met l'accent sur leur morphologie et leur structure ainsi que sur leurs propriétés rhéologiques, thermiques et mécaniques. Une étude approfondie de l'évolution de la morphologie du mélange au cours de l’extrusion a été effectuée car ce paramètre est la clé pour optimiser le procédé et obtenir les meilleures propriétés pour le matériau final. Ceci représente la contribution plus importante de ces travaux de recherche. / The main objective of this work was the production of dynamically revulcanized blends containing HDPE and GTR devulcanized by microwaves. It comes against a big global problem which is the waste disposal of vulcanized elastomers, especially tires, which bring with them serious environmental and public health problems, since these materials require long periods of time to degrade naturally due to their structure of cross-linkings, and the presence of stabilizers and other additives in its formulation. A way of using the GTR that has been widely studied by researchers is as polymer blends in which one of the phases is a thermoplastic polymer. In this context, the role of elastomers devulcanization is to increase the interaction between raw and recycled material, reducing the degradation of properties of the finished product with its incorporation and making it possible the increase of the recycled rubber amount in the compound recycled rubber/thermoplastic. The devulcanization transformes devulcanized elastomer into a fluid material, allowing a better control of the particle size during the mixing process of the blend by breaking processes in the application of high shear rates. In addition, by becoming a fluid material, it is possible the incorporation of a higher amount of elastomer to the thermoplastic without great damage to its processability. However, the literature does not have works in which the study of the processing parameters of dynamically revulcanized blends containing devulcanized elastomer, as well as the influence of addition of clays from different shapes (lamellar and tubular) on their final properties, especially on rheological properties, which sets out the present work. Summarizing, this work aims to propose a possible solution to the problem of solid waste disposing by producing a dynamically revulcanized blend containing HDPE and GTR devulcanized by microwaves, in addition to decrease some gaps observed currently in the literature from the obtained results.