Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA
Autor(a) principal: | |
---|---|
Data de Publicação: | 2008 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFSCAR |
Texto Completo: | https://repositorio.ufscar.br/handle/ufscar/655 |
Resumo: | In this work, we sought to modify PHB, processing it in the melted state, and to evaluate the effect of the modifications on its mechanical properties and biodegradation characteristics. The following systems were therefore studied: a PHB/EVA blend, in a 90/10 ratio, with an ethylene-co-vinyl acetate copolymer containing 28% of VA; a PHB and PHB/EVA blend with 1% of Boron Nitride (BN) nucleant; a PHB and PHB/EVA blend with 0,35% of HPN nucleant ( Hyperform Nucleant ); and a PHB/EVA blend with 5% of Elvaloy PTW, which was used as a compatibilizer. These systems were characterized by thermal, mechanical, morphological and biodegradation analyses using the following techniques: Melt Flow Index (MFI), Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), Dynamic Mechanical Thermal Analysis (DMTA), Size Exclusion Chromatography (SEC), Tensile Mechanical and Izod Impact (notched) Tests, Wide-Angle X-ray Diffraction (WAXD), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). The biodegradability test involved burying the samples in a suitable compost for 60, 120 and 180 days. The DCS analysis indicated that Boron Nitride was an effective nucleating agent for the PHB. However, the HPN did not act as a nucleant on this polymer, but instead, induced degradation of the PHB upon heating, as indicated by MFI, DSC and TG. Moreover, the addition of BN or even EVA did not improve the mechanical properties of PHB, and Elvaloy PTW did not act as a compatibilizing agent for the PHB/EVA blend. The HPN was found to interact antagonically with the PHB, which displayed extremely low impact strength values and widely dispersed results. The SEM and AFM analyses revealed poor distribution and inadequate dispersion of EVA in the PHB matrix. In addition, the AFM technique indicated that the PHB topography displayed the presence of pores, which undoubtedly, combined with the other factors, hindered its modification. Biodegradation was found to be strongly composition-dependent, since the addition of 10% of EVA to the PHB significantly accelerated the degradation of the PHB in this blend. In other words, the PHB probably exhibited disordered chain packing in the proximities of the EVA, facilitating the process of biodegradation by microorganisms. Hence, this study demonstrated the difficulty of modifying PHB, since it involves a variety of factors, as well as the possibility of developing PHB-based materials that biodegrade more or less rapidly according to the needs of a specific application. |
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Falcone, Daniele Maria BrunoAgnelli, José Augusto Marcondeshttp://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4727641E3http://lattes.cnpq.br/8438856690765294fe843280-dbbf-48a5-b0d7-a0a1c82a508c2016-06-02T19:09:59Z2008-06-242016-06-02T19:09:59Z2008-03-19FALCONE, Daniele Maria Bruno. Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA. 2008. 207 f. Tese (Doutorado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2008.https://repositorio.ufscar.br/handle/ufscar/655In this work, we sought to modify PHB, processing it in the melted state, and to evaluate the effect of the modifications on its mechanical properties and biodegradation characteristics. The following systems were therefore studied: a PHB/EVA blend, in a 90/10 ratio, with an ethylene-co-vinyl acetate copolymer containing 28% of VA; a PHB and PHB/EVA blend with 1% of Boron Nitride (BN) nucleant; a PHB and PHB/EVA blend with 0,35% of HPN nucleant ( Hyperform Nucleant ); and a PHB/EVA blend with 5% of Elvaloy PTW, which was used as a compatibilizer. These systems were characterized by thermal, mechanical, morphological and biodegradation analyses using the following techniques: Melt Flow Index (MFI), Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), Dynamic Mechanical Thermal Analysis (DMTA), Size Exclusion Chromatography (SEC), Tensile Mechanical and Izod Impact (notched) Tests, Wide-Angle X-ray Diffraction (WAXD), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). The biodegradability test involved burying the samples in a suitable compost for 60, 120 and 180 days. The DCS analysis indicated that Boron Nitride was an effective nucleating agent for the PHB. However, the HPN did not act as a nucleant on this polymer, but instead, induced degradation of the PHB upon heating, as indicated by MFI, DSC and TG. Moreover, the addition of BN or even EVA did not improve the mechanical properties of PHB, and Elvaloy PTW did not act as a compatibilizing agent for the PHB/EVA blend. The HPN was found to interact antagonically with the PHB, which displayed extremely low impact strength values and widely dispersed results. The SEM and AFM analyses revealed poor distribution and inadequate dispersion of EVA in the PHB matrix. In addition, the AFM technique indicated that the PHB topography displayed the presence of pores, which undoubtedly, combined with the other factors, hindered its modification. Biodegradation was found to be strongly composition-dependent, since the addition of 10% of EVA to the PHB significantly accelerated the degradation of the PHB in this blend. In other words, the PHB probably exhibited disordered chain packing in the proximities of the EVA, facilitating the process of biodegradation by microorganisms. Hence, this study demonstrated the difficulty of modifying PHB, since it involves a variety of factors, as well as the possibility of developing PHB-based materials that biodegrade more or less rapidly according to the needs of a specific application.Neste trabalho, buscou-se modificar o PHB utilizando-se do processamento no estado fundido, e avaliar o efeito das modificações sobre as propriedades mecânicas e características de biodegradação. Assim, os seguintes sistemas foram estudados: blenda PHB/EVA, na razão 90/10, com um copolímero etileno-co-acetato de vinila contento 28% de VA; PHB e blenda PHB/EVA com 1% do agente nucleante Nitreto de Boro (BN); PHB e blenda PHB/EVA com 0,35% do agente nucleante HPN ( Hyperform Nucleant ); blenda PHB/EVA com 5% de Elvaloy PTW, o qual foi utilizado como compatibilizante. Com estes sistemas foram efetuadas caracterizações térmicas, mecânicas, morfológicas e de biodegradação utilizando-se várias técnicas: medidas de Índice de Fluidez (MFI), Calorimetria Exploratória Diferencial (DSC), Termogravimetria (TG), Análise Térmica Dinâmico-Mecânica (DMTA), Cromatografia de Exclusão por Tamanho (SEC), Ensaios Mecânicos de Tração e de Impacto Izod com entalhe, Difração de Raio-X de Alto Ângulo (WAXS), Microscopia Eletrônica de Varredura (MEV), Microscopia de Força Atômica (AFM). O ensaio de biodegradabilidade foi efetuado enterrando-se as amostras em um composto apropriado por 60, 120 e 180 dias. Como evidenciado por DSC, o Nitreto de Boro mostrou-se como um agente nucleante efetivo para o PHB. Já o HPN não atuou como tal para este polímero, e conforme comprovado por MFI, DSC e TG, induziu à degradação do PHB mediante aquecimento. Em relação às características mecânicas, a adição de BN ou mesmo EVA não propriciou melhora nas propriedades mecânicas do PHB, e o Elvaloy PTW não atuou como agente compatibilizante para a blenda PHB/EVA. O HPN mostrou interação antagônica com o PHB, que exibiu valores de Resistência ao Impacto extremamente baixos e com grande dispersão dos resultados. Conforme demonstrado por MEV e AFM, não houve boa distribuição e adequada dispersão do EVA na matriz de PHB. Além disto, a técnica de AFM evidenciou que o PHB exibiu uma topografia com a presença de alguns poros, o que certamente em conjunto aos demais fatores dificultou a sua modificação. Em relação à biodegradação, esta mostrou-se fortemente dependente da composição, visto que a adição de EVA ao PHB, no teor de 10%, induziu a um aumento significativo na velocidade de biodegradação do PHB nesta blenda. Ou seja, provavelmente o PHB exibiu um empacotamento de cadeia desordenado nas proximidades do EVA, facilitando o processo de biodegradação por microrganismos. Assim, este estudo mostrou a dificuldade na modificação do PHB, visto que vários fatores estão envolvidos, e além disto, a possibilidade de desenvolver materiais baseados em PHB que se biodegradem mais ou menos rapidamente de acordo com a necessidade de uma aplicação específica.Financiadora de Estudos e Projetosapplication/pdfporUniversidade Federal de São CarlosPrograma de Pós-Graduação em Ciência e Engenharia de Materiais - PPGCEMUFSCarBRPolímerosPoli (Hidroxibutirato)BiodegradaçãoAgentes nucleantesBlendas poliméricasENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICAModificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVAinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesis-1-1007567da-759c-46ab-a037-bd8640627838info:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINAL1831.pdfapplication/pdf6632154https://repositorio.ufscar.br/bitstream/ufscar/655/1/1831.pdfd9d90de595d72d589d4a2dec222ce6a1MD51THUMBNAIL1831.pdf.jpg1831.pdf.jpgIM Thumbnailimage/jpeg6407https://repositorio.ufscar.br/bitstream/ufscar/655/2/1831.pdf.jpg0594b4bc48460d373ba8b0ae0a4388e6MD52ufscar/6552023-09-18 18:30:39.852oai:repositorio.ufscar.br:ufscar/655Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:30:39Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA |
title |
Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA |
spellingShingle |
Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA Falcone, Daniele Maria Bruno Polímeros Poli (Hidroxibutirato) Biodegradação Agentes nucleantes Blendas poliméricas ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA |
title_short |
Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA |
title_full |
Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA |
title_fullStr |
Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA |
title_full_unstemmed |
Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA |
title_sort |
Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA |
author |
Falcone, Daniele Maria Bruno |
author_facet |
Falcone, Daniele Maria Bruno |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/8438856690765294 |
dc.contributor.author.fl_str_mv |
Falcone, Daniele Maria Bruno |
dc.contributor.advisor1.fl_str_mv |
Agnelli, José Augusto Marcondes |
dc.contributor.advisor1Lattes.fl_str_mv |
http://genos.cnpq.br:12010/dwlattes/owa/prc_imp_cv_int?f_cod=K4727641E3 |
dc.contributor.authorID.fl_str_mv |
fe843280-dbbf-48a5-b0d7-a0a1c82a508c |
contributor_str_mv |
Agnelli, José Augusto Marcondes |
dc.subject.por.fl_str_mv |
Polímeros Poli (Hidroxibutirato) Biodegradação Agentes nucleantes Blendas poliméricas |
topic |
Polímeros Poli (Hidroxibutirato) Biodegradação Agentes nucleantes Blendas poliméricas ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA |
dc.subject.cnpq.fl_str_mv |
ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA |
description |
In this work, we sought to modify PHB, processing it in the melted state, and to evaluate the effect of the modifications on its mechanical properties and biodegradation characteristics. The following systems were therefore studied: a PHB/EVA blend, in a 90/10 ratio, with an ethylene-co-vinyl acetate copolymer containing 28% of VA; a PHB and PHB/EVA blend with 1% of Boron Nitride (BN) nucleant; a PHB and PHB/EVA blend with 0,35% of HPN nucleant ( Hyperform Nucleant ); and a PHB/EVA blend with 5% of Elvaloy PTW, which was used as a compatibilizer. These systems were characterized by thermal, mechanical, morphological and biodegradation analyses using the following techniques: Melt Flow Index (MFI), Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), Dynamic Mechanical Thermal Analysis (DMTA), Size Exclusion Chromatography (SEC), Tensile Mechanical and Izod Impact (notched) Tests, Wide-Angle X-ray Diffraction (WAXD), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). The biodegradability test involved burying the samples in a suitable compost for 60, 120 and 180 days. The DCS analysis indicated that Boron Nitride was an effective nucleating agent for the PHB. However, the HPN did not act as a nucleant on this polymer, but instead, induced degradation of the PHB upon heating, as indicated by MFI, DSC and TG. Moreover, the addition of BN or even EVA did not improve the mechanical properties of PHB, and Elvaloy PTW did not act as a compatibilizing agent for the PHB/EVA blend. The HPN was found to interact antagonically with the PHB, which displayed extremely low impact strength values and widely dispersed results. The SEM and AFM analyses revealed poor distribution and inadequate dispersion of EVA in the PHB matrix. In addition, the AFM technique indicated that the PHB topography displayed the presence of pores, which undoubtedly, combined with the other factors, hindered its modification. Biodegradation was found to be strongly composition-dependent, since the addition of 10% of EVA to the PHB significantly accelerated the degradation of the PHB in this blend. In other words, the PHB probably exhibited disordered chain packing in the proximities of the EVA, facilitating the process of biodegradation by microorganisms. Hence, this study demonstrated the difficulty of modifying PHB, since it involves a variety of factors, as well as the possibility of developing PHB-based materials that biodegrade more or less rapidly according to the needs of a specific application. |
publishDate |
2008 |
dc.date.available.fl_str_mv |
2008-06-24 2016-06-02T19:09:59Z |
dc.date.issued.fl_str_mv |
2008-03-19 |
dc.date.accessioned.fl_str_mv |
2016-06-02T19:09:59Z |
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info:eu-repo/semantics/publishedVersion |
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info:eu-repo/semantics/doctoralThesis |
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doctoralThesis |
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publishedVersion |
dc.identifier.citation.fl_str_mv |
FALCONE, Daniele Maria Bruno. Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA. 2008. 207 f. Tese (Doutorado 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/655 |
identifier_str_mv |
FALCONE, Daniele Maria Bruno. Modificação do Poli(hidroxibutirato) PHB com nucleantes e com o copolímero (etileno-co-acetato de vinila) - EVA. 2008. 207 f. Tese (Doutorado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2008. |
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