Estudo da produção e reciclagem de blendas de polietileno e amido termoplástico visando aplicações no setor de embalagens
Data
2022-10-31
Autores
Santos, Natali Bomfim 
Orientadores
Lemes, Ana Paula
Tipo
Dissertação de mestrado
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Resumo
Nesse trabalho, blendas de polietileno de baixa densidade (LDPE) e amido termoplástico (TPS) foram produzidos variando-se a proporção entre esses componentes, sem e com a utilização do LLDPE-g-MA como agente compatibilizante. Primeiramente o TPS foi preparado realizando-se a plastificação do amido com glicerol, em uma extrusora dupla rosca. As blendas de LDPE e TPS também foram preparadas em uma extrusora dupla rosca. As blendas com e sem adição de agente compatibilizante foram preparadas variando a proporção do TPS de 10 a 70% em massa. As blendas LDPE/TPS e LDPE/LLDPE-g-MA/TPS foram caracterizadas com relação a suas propriedades mecânicas por meio de ensaios de tração e impacto, propriedades térmicas, por meio de análise termogravimétrica (TGA) e calorimetria exploratória diferencial (DSC), ensaio de difração de raio-X (DRX), microscopia eletrônica de varredura (MEV), espectroscopia de infravermelho com transformada de Fourier (FT-IR) e avaliação da molhabilidade dos filmes pelo método da gota séssil. Também foi realizado um estudo sobre a reciclagem das blendas de LDPE/TPS e LDPE/LLDPE-g-MA/TPS, utilizando-se duas rotas. Na primeira as blendas produzidas foram submetidas a dois novos ciclos de reprocessamento em extrusora com obtenção de corpos de prova por moldagem por compressão com aquecimento. Na segunda rota foi realizada uma etapa de lavagem para remoção do amido, e avaliado a viabilidade de reinserção do LDPE pós lavagem num novo processamento.
In this work, blends of low-density polyethylene (LDPE) and thermoplastic starch (TPS) were produced by varying the proportion between these components, without and with the use of LLDPE-g-MA as a compatibilizing agent. First, the TPS was prepared by plasticizing the starch with glycerol in a twin-screw extruder. The LDPE and TPS blends were also prepared in a twin-screw extruder. Blends with and without addition of compatibilizing agent were prepared by varying the TPS proportion from 10 to 70% by mass. The LDPE/TPS and LDPE/LLDPE-g-MA/TPS blends were characterized in relation to their mechanical properties through tensile and impact tests, thermal properties, through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) , X-ray diffraction test (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and assessment of film wettability using the sessile drop method. A study was also carried out on the recycling of LDPE/TPS and LDPE/LLDPE-g-MA/TPS blends, using two routes. First, the blends produced were subjected to two new reprocessing cycles in an extruder to obtain test specimens by compression molding with heating. In the second route, a washing step was carried out to remove the starch, and the feasibility of reinserting the LDPE after washing in a new process was evaluated.
In this work, blends of low-density polyethylene (LDPE) and thermoplastic starch (TPS) were produced by varying the proportion between these components, without and with the use of LLDPE-g-MA as a compatibilizing agent. First, the TPS was prepared by plasticizing the starch with glycerol in a twin-screw extruder. The LDPE and TPS blends were also prepared in a twin-screw extruder. Blends with and without addition of compatibilizing agent were prepared by varying the TPS proportion from 10 to 70% by mass. The LDPE/TPS and LDPE/LLDPE-g-MA/TPS blends were characterized in relation to their mechanical properties through tensile and impact tests, thermal properties, through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) , X-ray diffraction test (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and assessment of film wettability using the sessile drop method. A study was also carried out on the recycling of LDPE/TPS and LDPE/LLDPE-g-MA/TPS blends, using two routes. First, the blends produced were subjected to two new reprocessing cycles in an extruder to obtain test specimens by compression molding with heating. In the second route, a washing step was carried out to remove the starch, and the feasibility of reinserting the LDPE after washing in a new process was evaluated.
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Dissertação de Mestrado