DIONE PEREIRA DE CASTRO
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Artigo IPEN-doc 27227 Characterization using X-ray diffraction and study of the crystallinity of the thermoplastic starch/poly(butylene adipate-co-terephthalate) blends irradiated by gamma rays2020 - CASTRO, DIONE P. de; GARCIA, RAFAEL H.L.; SILVA, LEONARDO G. de A. eThe aim of this study was to analyze the changes in the structure and crystallinity of non-irradiated and irradiated thermoplastic starch blends (TPS)/poly (butylene adipate-co-terephthalate) - PBAT and also to evaluate the behavior of castor oil replacing glycerol. In this work, the characterization was performed by using X-ray diffraction (XRD), in which the crystallinity index (IC) of non-irradiated and irradiated blends of TPS/PBAT was calculated, through the software Bruker DIFFRAC.EVA® v4.22. For the plastification of the TPS, glycerol, castor oil and TWEEN® 80 were used to verify their compatibility and establish a comparison among the blends. The samples were prepared by extrusion and irradiated at 25 kGy with gamma rays with a 60Co source. However, the crystallinity indexes of the blends were altered according to the plasticizer used and the use of TWEEN® 80. Thus, it was concluded that replacing glycerol with castor oil is feasible in TPS/PBAT blends.Artigo IPEN-doc 26657 Effects of gamma radiation on the properties of the thermoplastic starch/poly (butylene adipate-co-terephthalate) blends2019 - CASTRO, DIONE P. de; SARTORI, MARIANA do N.; SILVA, LEONARDO G. de A. eThe development of blends made from matrices of synthetic biodegradable polymers, and natural additives, are considered less environmentally aggressive materials. This work aimed to study the effects of gamma radiation on the properties of the thermoplastic starch (TPS)/poly(butylene adipateco- terephthalate) (PBAT). In this work, blends of TPS/PBAT were prepared with glycerol, castor oil and TWEEN® 80, which were prepared by extrusion and then subjected to the radiation process and characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). 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. 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 oi l with glycerol in TPS/PBAT blends.Artigo IPEN-doc 26293 XRD characterization thermoplastic STARCH/poly (butylene adipate-co-terephthalate) (TPS/PBAT) blends irradiated by gamma rays2019 - CASTRO, DIONE P. de; GARCIA, RAFAEL H.L.; SILVA, LEONARDO G. de A. eThe aim of this research was to check the changes in the structure and crystallinity of non-irradiated and irradiated thermoplastic starch blends (TPS)/poly (butylene adipate-co-terephthalate) - PBAT and also to evaluate the behavior of castor oil in place of glycerol. In this work, the characterization was performed by X-ray diffraction (XRD), in which the crystallinity index (IC) of non-irradiated and irradiated blends of TPS/PBAT was calculated. For plastification of the TPS, glycerol, castor oil and TWEEN® 80 were used to verify the compatibility and compare the blends with each other. The samples were prepared by extrusion and irradiated at 25 kGy with gamma rays from a 60Co source. However, the crystallinity indexes of the blends were altered according to the plasticizer used and the use of TWEEN® 80. Thus, it been concluded that glycerol substitution by castor oil is feasible in TPS/PBAT blends.Dissertação IPEN-doc 25675 Efeitos da radiação gama nas propriedades de blendas de amido termoplástico e suas misturas com poli(butileno adipato-co-tereftalato)2019 - CASTRO, DIONE P. deDiversas 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.