Desenvolvimento de compósito a base de amido termoplástico (TPS) reforçado com fibras de açaí e polietileno de baixa densidade (PEBD)

Abstract

In recent years, a great worldwide interest has arisen in the development of new products that allow the use of raw materials from renewable sources. In this context, polymeric materials have received special attention because they raise several issues such as non-biodegradability, the difficulty of recycling and because they come from a non-renewable source. Therefore, the opportunity arises to seek to develop polymeric composites based on thermoplastic starch reinforced with açaí fiber and low density polyethylene. Thermoplastic starch has shown promise in replacing petroleum-derived polymers, however, it has limitations in its use, such as high water absorption and low mechanical strength, and with that, the idea of using açaí fiber, a residue with high availability and without adequate destination, with the objective of improving the properties of the polymeric composite in the face of the limitations of thermoplastic starch, in addition to adding value to the lignocellulosic residue. This work was carried out in two stages, with six treatments being evaluated in the first, with three variations in the percentage of açaí fibers (0, 10 and 20%) and two of LDPE (20 and 30%). In the second stage of the work, four treatments were evaluated, with substitution percentages of 0, 20, 80 and 100% of the LDPE/TPS/FA composite by the LDPEr. A chemical, physical and anatomical characterization of the açaí fibers was carried out. The composites obtained were evaluated through X-ray diffraction, Fourier transform infrared spectroscopy, tensile test, photodegradation, scanning electron microscopy, thermogravimetric analysis and density. In the first stage, combining a product with low cost and good mechanical performance, the TPS60PE20F20 treatment stood out among the others, both due to the increase in mechanical properties, as well as the lower use of LDPE. In the second stage, the LDPEr20TPF80 treatment showed better results, also due to the improvement in mechanical properties and the lower percentage of PEDB used.