Estudo das propriedades reológicas de nanocompósitos para a produção de filmes tubulares

Detalhes bibliográficos
Autor(a) principal: Beatrice, Cesar Augusto Gonçalves
Data de Publicação: 2008
Tipo de documento: Dissertação
Idioma: por
Título da fonte: Repositório Institucional da UFSCAR
Texto Completo: https://repositorio.ufscar.br/handle/ufscar/785
Resumo: In this work, the use of rheological measurements in substitution or complementation to methods normally employed in the characterization of nanocomposites, such as X-ray diffraction (WAXS) and transmission electron microscopy (TEM), was evaluated. Two polymeric matrices with different chemical structures and polarities and two organophilic nanoclays modified with organic surfactants, which were compatible with the respective polymer matrix, were used. Thus, polyamide 6 (PA6) and high density polyethylene (HDPE) nanocomposites were obtained by melt mixing and blown as films. WAXS measurements showed intercalated structures in the HDPE nanocomposites and exfoliated structures in the PA6 nanocomposites. Shear oscillatory rheological experiments were done to evaluate the clay dispersion and distribution in the polymer matrices, which indicated the presence of a poor dispersion in the HDPE nanocomposites, differently of the PA6 nanocomposites. Shear steady and transient rheological measurements indicated that higher interactions between PA6 and the nanoclay modified with a polar surfactant and inside the EVA masterbatches occurred. From the rheological, morphological, mechanical and transport analysis it was found that the addition of clay modified the interfacial interactions between HDPE and EVA, increasing the system compatibility. In both systems, there was an increase in elastic modulus, yielding and rupture behaviors and barrier properties. In conclusion, the rheological characterization of nanocomposites provides further information about the nanoclay dispersion and distribution in the polymer matrix, in addition to quantify the interactions between the components. However, it can not substitute the usual methods of characterization of the nanocomposites, such as WAXS and TEM.
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spelling Beatrice, Cesar Augusto GonçalvesBretas, Rosario Elida Sumanhttp://genos.cnpq.br:12010/dwlattes/owa/consultapesq.prc_querylisthttp://lattes.cnpq.br/6023179925944867d506efb8-3193-47ec-beb1-069a3c6743272016-06-02T19:11:55Z2009-11-122016-06-02T19:11:55Z2008-07-08BEATRICE, Cesar Augusto Gonçalves. Rheological characterization of nanocomposites for a blown film extrusion process. 2008. 229 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2008.https://repositorio.ufscar.br/handle/ufscar/785In this work, the use of rheological measurements in substitution or complementation to methods normally employed in the characterization of nanocomposites, such as X-ray diffraction (WAXS) and transmission electron microscopy (TEM), was evaluated. Two polymeric matrices with different chemical structures and polarities and two organophilic nanoclays modified with organic surfactants, which were compatible with the respective polymer matrix, were used. Thus, polyamide 6 (PA6) and high density polyethylene (HDPE) nanocomposites were obtained by melt mixing and blown as films. WAXS measurements showed intercalated structures in the HDPE nanocomposites and exfoliated structures in the PA6 nanocomposites. Shear oscillatory rheological experiments were done to evaluate the clay dispersion and distribution in the polymer matrices, which indicated the presence of a poor dispersion in the HDPE nanocomposites, differently of the PA6 nanocomposites. Shear steady and transient rheological measurements indicated that higher interactions between PA6 and the nanoclay modified with a polar surfactant and inside the EVA masterbatches occurred. From the rheological, morphological, mechanical and transport analysis it was found that the addition of clay modified the interfacial interactions between HDPE and EVA, increasing the system compatibility. In both systems, there was an increase in elastic modulus, yielding and rupture behaviors and barrier properties. In conclusion, the rheological characterization of nanocomposites provides further information about the nanoclay dispersion and distribution in the polymer matrix, in addition to quantify the interactions between the components. However, it can not substitute the usual methods of characterization of the nanocomposites, such as WAXS and TEM.Neste trabalho avaliou-se o uso de medidas de propriedades reológicas na substituição ou complementação de métodos geralmente empregados na caracterização das estruturas de nanocompósitos, tais como a difração de raios-x de alto ângulo (WAXS) e a microscopia eletrônica de transmissão (MET). Para tanto, foram utilizadas duas matrizes poliméricas com diferentes polaridades e duas argilas organofílicas tratadas com surfatantes compatíveis com a respectiva matriz polimérica. Assim, nanocompósitos de poliamida 6 (PA6) e de polietileno de alta densidade (HDPE), este último compatibilizado com um copolímero aleatório de etileno e acetato de vinila (EVA), foram produzidos através de mistura no estado fundido e posteriormente conformados na forma de filmes tubulares. Observou-se por WAXS que os nanocompósitos de HDPE possuíam estrutura intercalada enquanto que os de PA6 possuíam uma estrutura esfoliada. Para verificar o estado de dispersão e de distribuição das argilas nas matrizes poliméricas foram realizados ensaios reológicos em regime oscilatório de cisalhamento juntamente com análises de MET, os quais mostraram para os nanocompósitos de HDPE um baixo nível de dispersão, diferentemente do observado nos nanocompósitos de PA6. Já os ensaios reológicos em regime permanente de cisalhamento e também no regime transiente mostraram que as interações entre polímero e argila eram mais fortes nos nanocompósitos de PA6 e nos concentrados de EVA do que nos nanocompósitos de HDPE. Através das analises reológicas, morfológicas e das propriedades mecânicas e de permeação, concluiu-se que a adição de argila promoveu uma significativa alteração nas interações interfaciais da blenda HDPE/EVA, que era a matriz dos nanocompósitos de HDPE, levando a uma maior compatibilização do sistema. Em ambos os sistemas houve uma melhora no módulo elástico, no comportamento de escoamento e de ruptura, além de melhores propriedades de barreira. Por fim, concluiu-se que as medidas das propriedades reológicas de nanocompósitos podem fornecer informações complementares a respeito do estado de dispersão e de distribuição da nanocarga na matriz polimérica, além de quantificar as interações existentes entre os componentes; mas que elas não podem substituir completamente as análises de WAXS e MET.Universidade Federal de Minas Geraisapplication/pdfporUniversidade Federal de São CarlosPrograma de Pós-Graduação em Ciência e Engenharia de Materiais - PPGCEMUFSCarBRReologiaNanocompósitosFilmes tubularesProcesso de extrusãoENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICAEstudo das propriedades reológicas de nanocompósitos para a produção de filmes tubularesRheological characterization of nanocomposites for a blown film extrusion processinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesis-1-1e983e14c-124c-422a-a96e-24e26346a86binfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINAL2472.pdfapplication/pdf8517687https://repositorio.ufscar.br/bitstream/ufscar/785/1/2472.pdfc68168cc3ba0a88a5a7c2a8ee50ea205MD51THUMBNAIL2472.pdf.jpg2472.pdf.jpgIM Thumbnailimage/jpeg6128https://repositorio.ufscar.br/bitstream/ufscar/785/2/2472.pdf.jpg4e1838bd06fac89ea08326c67ea7555fMD52ufscar/7852023-09-18 18:30:40.119oai:repositorio.ufscar.br:ufscar/785Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:30:40Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false
dc.title.por.fl_str_mv Estudo das propriedades reológicas de nanocompósitos para a produção de filmes tubulares
dc.title.alternative.eng.fl_str_mv Rheological characterization of nanocomposites for a blown film extrusion process
title Estudo das propriedades reológicas de nanocompósitos para a produção de filmes tubulares
spellingShingle Estudo das propriedades reológicas de nanocompósitos para a produção de filmes tubulares
Beatrice, Cesar Augusto Gonçalves
Reologia
Nanocompósitos
Filmes tubulares
Processo de extrusão
ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA
title_short Estudo das propriedades reológicas de nanocompósitos para a produção de filmes tubulares
title_full Estudo das propriedades reológicas de nanocompósitos para a produção de filmes tubulares
title_fullStr Estudo das propriedades reológicas de nanocompósitos para a produção de filmes tubulares
title_full_unstemmed Estudo das propriedades reológicas de nanocompósitos para a produção de filmes tubulares
title_sort Estudo das propriedades reológicas de nanocompósitos para a produção de filmes tubulares
author Beatrice, Cesar Augusto Gonçalves
author_facet Beatrice, Cesar Augusto Gonçalves
author_role author
dc.contributor.authorlattes.por.fl_str_mv http://lattes.cnpq.br/6023179925944867
dc.contributor.author.fl_str_mv Beatrice, Cesar Augusto Gonçalves
dc.contributor.advisor1.fl_str_mv Bretas, Rosario Elida Suman
dc.contributor.advisor1Lattes.fl_str_mv http://genos.cnpq.br:12010/dwlattes/owa/consultapesq.prc_querylist
dc.contributor.authorID.fl_str_mv d506efb8-3193-47ec-beb1-069a3c674327
contributor_str_mv Bretas, Rosario Elida Suman
dc.subject.por.fl_str_mv Reologia
Nanocompósitos
Filmes tubulares
Processo de extrusão
topic Reologia
Nanocompósitos
Filmes tubulares
Processo de extrusão
ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA
dc.subject.cnpq.fl_str_mv ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA
description In this work, the use of rheological measurements in substitution or complementation to methods normally employed in the characterization of nanocomposites, such as X-ray diffraction (WAXS) and transmission electron microscopy (TEM), was evaluated. Two polymeric matrices with different chemical structures and polarities and two organophilic nanoclays modified with organic surfactants, which were compatible with the respective polymer matrix, were used. Thus, polyamide 6 (PA6) and high density polyethylene (HDPE) nanocomposites were obtained by melt mixing and blown as films. WAXS measurements showed intercalated structures in the HDPE nanocomposites and exfoliated structures in the PA6 nanocomposites. Shear oscillatory rheological experiments were done to evaluate the clay dispersion and distribution in the polymer matrices, which indicated the presence of a poor dispersion in the HDPE nanocomposites, differently of the PA6 nanocomposites. Shear steady and transient rheological measurements indicated that higher interactions between PA6 and the nanoclay modified with a polar surfactant and inside the EVA masterbatches occurred. From the rheological, morphological, mechanical and transport analysis it was found that the addition of clay modified the interfacial interactions between HDPE and EVA, increasing the system compatibility. In both systems, there was an increase in elastic modulus, yielding and rupture behaviors and barrier properties. In conclusion, the rheological characterization of nanocomposites provides further information about the nanoclay dispersion and distribution in the polymer matrix, in addition to quantify the interactions between the components. However, it can not substitute the usual methods of characterization of the nanocomposites, such as WAXS and TEM.
publishDate 2008
dc.date.issued.fl_str_mv 2008-07-08
dc.date.available.fl_str_mv 2009-11-12
2016-06-02T19:11:55Z
dc.date.accessioned.fl_str_mv 2016-06-02T19:11:55Z
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dc.identifier.citation.fl_str_mv BEATRICE, Cesar Augusto Gonçalves. Rheological characterization of nanocomposites for a blown film extrusion process. 2008. 229 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2008.
dc.identifier.uri.fl_str_mv https://repositorio.ufscar.br/handle/ufscar/785
identifier_str_mv BEATRICE, Cesar Augusto Gonçalves. Rheological characterization of nanocomposites for a blown film extrusion process. 2008. 229 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2008.
url https://repositorio.ufscar.br/handle/ufscar/785
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