Desenvolvimento de bioprodutos a partir de fibras de frutos de Euterpe precatoria, Paullinia cupana, Astrocaryum aculeatum e polipropileno

Abstract

Agroindustrial waste from açaí (Euterpe precatoria), tucumã (Astrocaryum aculeatum), and guaraná (Paullinia cupana var. sorbilis (Mart.) Ducke, synonym Paullinia cupana) are discarded, most of the time, inappropriately, contributing to environmental pollution. In order to present a solution to this problem, bioproducts (biocomposites) were developed with fibrous waste from açaí, guaraná, tucumã and polypropylene (PP). In this way, different combinations of bioproducts were produced by plastic injection, in a company in the Manaus Industrial Complex. The physicochemical, morphological, and thermal characteristics of the bioproducts were determined by Fourier transform infrared spectroscopy – attenuated total refletance (FTIR-ATR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and mechanical properties: tension and flexion. The results show that in bioproducts there is no formation of new crystalline phases during plastic injection. Thermogravimetric analyses indicate that the beginning of the decomposition of PP occurs at approximately 397 oC and ends at 475 oC, while in bioproducts it occurs at 300 oC, and ends at around 475 oC. Thermal transformations for PP occur at 437,3 oC and for bioproducts from 167,8 oC to 464,0 oC. Mechanical tensile tests show that the rupture of bioproducts occurs with the formation of microvoids typical of conglomerates with different phases. Despite this, the bioproducts produced have lower tensile strength than PP. But the same cannot be said for flexure, whose bioproducts have practically the same flexure as PP. Despite the results obtained in mechanical tests, bioproducts can still be considered materials applicable in plastic products that are less demanding in terms of traction and flexion. This statement is based on the reduction of around 10 % of PP, in addition to introducing sustainable raw materials into the composition of polymer matrices used in the plastic injection industry.