Avaliação da resistência à abrasividade de compósitos de polipropileno e resíduos de granito com potencial aplicação em componentes automotivos

Abstract

The utilization of polymer composites reinforced with ornamental rock waste, such as granite, has potential in the automotive industry due to its combined lightness and resistance. Essential features for optimizing vehicle energy efficiency and reducing greenhouse gas emissions. This material meets the growing demand for sustainable and economically viable solutions. This study aimed to evaluate the impact of incorporating different granite powder concentrations in polypropylene composites, focusing on abrasion resistance and potential automotive applications. The research contributes to the sustainable disposal of ornamental rock waste and the development of innovative materials for industry. Granite waste (Cinza Corumbá) and polypropylene were used as a matrix. Granite powder was incorporated at 10%, 20%, 30%, and 40% concentrations by mass, crushed, sieved to 45 mesh, and dried before processing. while the polypropylene was also pre-dried. The composites were extruded at 190°C and 200 rpm, followed by injection molding to produce test specimens. Tests included density, abrasion resistance, tensile strength, flexural strength, and impact resistance. The characterization of the composites included analysis by Scanning Electron Microscopy (SEM), density tests, mechanical properties and abrasion resistance, evaluating the matrix-filler interaction and the impact of the variation of granite powder. The density increased up to 37% with 40% load, while the tensile and flexural modulus increased by 54% and 80%, respectively. However, the tensile and flexural strengths reduced by up to 47% and 9%, due to poor adhesion between matrix and filler. The impact resistance was higher with 10% powder (42%), but decreased at higher concentrations. The abrasion resistance worsened, with mass loss of up to 236% at the highest concentrations. The SEM confirmed the heterogeneous distribution of the powder and the formation of craters. It is concluded that granite powder increases stiffness, but impairs mechanical and wear resistance at high concentrations. Modifications, such as compatibilizers or adjustment of the granulometry, are suggested to improve performance. [resumo fornecido pelo autor]