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Master's Dissertation
DOI
Document
Author
Full name
Dione Pereira de Castro
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2019
Supervisor
Committee
Silva, Leonardo Gondim de Andrade e (President)
Júnior, Antônio Hortêncio Munhoz
Valera, Ticiane Sanches
Title in Portuguese
Efeitos da radiação gama nas propriedades de blendas de amido termoplástico e suas misturas com poli(butileno adipato-co-tereftalato)
Keywords in Portuguese
blendas
PBAT
radiação gama
TPS
Abstract in Portuguese
Diversas alternativas têm sido buscadas para minimizar o impacto ambiental causado pelos polímeros convencionais. Uma importante alternativa é o uso de polímeros biodegradáveis; no entanto, em razão do seu custo elevado quando comparados com polímeros convencionais, surgiu à necessidade de desenvolver misturas poliméricas biodegradáveis utilizando aditivos naturais degradáveis, menos agressivos ao meio ambiente; os quais podem ser degradados pela ação de micro-organismos ou enzimas. Este trabalho teve como objetivo preparar blendas de amido termoplástico (thermoplastic starch, TPS) obtidos com glicerol, óleo de mamona (OM) e TWEEN® 80 com poli(butileno adipato-co-tereftalato) (PBAT), por extrusão. Posteriormente as blendas foram submetidas ao processo de irradiação com dose de 25 kGy e caracterizadas por análises termogravimétrica (TGA); calorimetria exploratória diferencial por fluxo de calor (DSC); espectroscopia vibracional de absorção no infravermelho por transformada de Fourier (FTIR); microscopia eletrônica de varredura (MEV); difração de raios X (DRX) e índice de cristalinidade (IC). Os resultados mostraram maior degradabilidade térmica para as blendas F2 (compostas por OM) e F3 (compostas por OM e TWEEN®80) em relação as blendas F0 (compostas por glicerol) e F1 (compostas por glicerol e TWEEN® 80). Observou-se uma boa interação química entre os componentes das misturas e a sua miscibilidade parcial para as misturas F0 e F1, comparadas com as demais. No entanto, as misturas F2 e F3 não tiveram fases co-contínuas; sendo que as curvas padrões de DRX das amostras não foram alteradas pela radiação gama. Os IC tiveram alterações antes e após a irradiação de acordo com o plastificante utilizado. Assim, as amostras irradiadas e não irradiadas não tiveram suas propriedades alteradas nos testes realizados. Pôde-se concluir que é viável a substituição do óleo de mamona por glicerol em blendas de TPS/PBAT.
Title in English
Effects of gamma radiation on the properties of the thermoplastic starch/poly(butylene adipate-co-terephthalate) blends
Keywords in English
blends
gamma radiation
PBAT
TPS
Abstract in English
Several alternatives have been sought to minimize the environmental impact caused by conventional polymers. The use of biodegradable polymers is an important alternative for this; however, when compared to conventional polymers, the biodegradable ones have higher costs. Thus, the development of polymeric blends using matrices of biodegradable and synthetic polymers with natural additive, less environmentally aggressive materials that can be degraded by the action of microorganisms or enzymes, was considered. This work aimed to prepare blends of thermoplastic starch (TPS) obtained with glycerol, castor oil (OM) and TWEEN® 80 with poly(butylene adipate-co-terephthalate) (PBAT) by extrusion. Posteriorly, the blends were submitted to the irradiation process at a dose of 25 kGy and characterized by thermogravimetric analysis (TGA); differential heat flow scanning calorimetry (DSC); Fourier transform infrared spectroscopy (FTIR); scanning electron microscopy (SEM); X-ray diffraction (XRD), and crystallinity index (CI). The results demonstrated increased thermal degradation for the F2 (composed by OM) and F3 (composed by OM and TWEEN® 80) regarding F0 (composed by glycerol) e F1 (composed by glycerol and TWEEN® 80) blends. A good blend component chemical interaction and partial miscibility for the blends F0 and F1 was observed and compared to the others. However, F2 and F3 blends did not present co-continuous phases; being that the XRD curve patterns were not altered by the gamma radiation. Changes in the crystallinity indexes (CI) were observed before and after irradiation according to the plasticizer used. The tests performed demonstrated that the irradiated and non-irradiated samples did not have their properties significantly altered. Thus, it was concluded that it is feasible to replace castor oil with glycerol in TPS/PBAT blends.
 
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2019CastroEfeitos.pdf (6.63 Mbytes)
Publishing Date
2019-06-13
 
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