Características estruturais e propriedades de biocompósito reforçado com fibras da vagem de moringa oleífera

Abstract

In this study, composites based on a virgin polypropylene (PP) matrix and natural fibers from Moringa oleífera applied as reinforcement were prepared. These composites were characterized by tensile tests, three-point bending, differential scanning calorimetry (DSC), thermogravimetry analisys (TGA), tribological tests, machining performance and fracture analysis by scanning electron microscopy (SEM). The addition of plant fibers shifted the initial degradation temperature of the composite 6 °C lower and the melting temperature 2 °C lower in relation to PP, indicating thermal compatibility between the matrix and the reinforcing agent. There was little dispersion in the sampling of mechanical properties data, the best results among the three groups were 21.88 MPa of tensile yield stress (σe), 1018.36 of tensile modulus of elasticity (E), 62.33 MPa of tensile strength limit (TRL), 23.89 MPa of flexural strength limit (σf), 2255.6 MPa of flexural modulus of elasticity (Eb) and maximum flexural deformation (εmax) of 5.29%. Results that demonstrated values included among the cataloged biocomposites but lower than commercial polypropylene. Explanations for these variations were sought through microscopy analyses on fractured surfaces, investigating morphology, adhesion and dispersion between fibers and matrix. Although the dry tribological performance was inferior to the reference material, under lubrication it showed superiority resulting in low friction. The matrix presented good support to the fibers, demonstrating low roughness. The benefit of using vegetable fibers such as those from Moringa oleifera is related to the reuse of biodegradable natural waste, strengthening global sustainability