Efeito dos ciclos de reprocessamento na morfologia e propriedades de blendas e bionanocompósitos poliméricos

Abstract

The inadequate disposal of polymer waste is causing environmental problems, since most polymers used in the industry take hundreds of years to decompose, resulting in accumulation in the environment, such as polypropylene. The search for solutions to this problem highlights the recycling and incorporation of biodegradable polymers to commonly produced plastics¸ as well as the production of bionanocomposites to obtain a material with better properties. In this context, this work evaluated the effects of recycling on the mechanical and morphological properties of polymer blends and bionanocomposites based on polypropylene (PP) and poly (3-hydroxybutyrate) (PHB), organophilic clay, PP-g-MA compatibilizer and erucamide . The material was submitted to seven consecutive extrusion cycles, and material was collected for cycles 1, 3, 5 and 7. The collected material was characterized by Scanning Electron Microscopy, where the presence of two distinct phases was observed in the blender. the addition of the clay, PP-g-MA and erucamide was observed a better adhesion in the phase of the materials; by Fourier Transform Infrared (FTIR) the functional groups characteristic of the material were identified, with few changes due to reprocessing; by X-ray diffraction an increase in the crystallinity of the materials was observed up to the 5th cycle of reprocessing and decrease in the 7th cycle. There were few changes in the mechanical properties of the blender and bionanocomposite, observed a significant increase of elasticity in the blender and by impact resistance the blends and bionanocomposites presented smaller results than the pure matrix, but it was noticed that the bionanocomposite had a growing increase in their values with the passing of the reprocessing cycles. By means of contact angle measurements, it was observed that the presence of cracks led to a decrease of the angle formed on the surface of the films and for the migration test the values presented are within the limits established by ANVISA for packaging applications food. The development of new polymer-based materials that combine good properties, which are biodegradable and that support reprocessing cycles, make blends and bionanocomposites promising alternatives for the processing industries.