Estudo do efeito da fibra de coco nas propriedades mecânicas do polipropileno

Abstract

The growing interest in materials that combine satisfactory mechanical performance and reduced environmental impact has driven the search for sustainable alternatives to conventional polymers. Polypropylene (PP), widely used due to its versatility and low cost, poses a significant environmental challenge due to its slow degradation. In this context, the incorporation of natural fibers, such as coconut fiber (CF), emerges as a promising strategy for developing more environmentally friendly composites. This study aimed to evaluate the effect of adding coconut fiber on the mechanical properties of polypropylene, investigating the influence of different concentrations of CF (1%, 5%, and 10%) and the presence of maleic anhydride (MA) as a compatibilizing agent. Composites were prepared using a traditional manufacturing process and characterized by tensile tests. The results indicated that the addition of coconut fiber, even with the presence of maleic anhydride, did not provide the expected reinforcement in tensile strength and elongation at break properties, which tended to decrease with increasing fiber concentration. Although the modulus of elasticity increased, indicating greater stiffness, it did not surpass that of pure PP at all concentrations. Critical analysis suggests that the lack of significant improvements can be attributed primarily to the challenges inherent in the artisanal manufacturing process, which resulted in poor fiber homogenization in the polymer matrix and weak interfacial adhesion. These process limitations compromised effective load transfer, causing the fiber to act more as a stress concentrator than as a reinforcement. It is concluded that, despite the potential of coconut fiber as a sustainable alternative, rigorous optimization of the manufacturing process and compatibilization is crucial to maximize the mechanical performance of these composites.