Mechanical properties and friction coefficient of hybrid polypropylene Entada mannii composites

The current study evaluates the mechanical properties and friction coefficient of polypropylene based composites reinforced with particulate derivatives from Entada mannii fiber. The composites were fabricated by mixing different ratios of fiber ash (FA) and fiber particulates (FP) with polypropylene matrix and compounded using compression moulding method. Tensile and flexural properties, impact strength, hardness and friction coefficient were assessed, while scanning electron microscopy (SEM) was used for structural and morphological studies of the composites. The results show that the tensile, flexural, impact and hardness properties of all the composites were enhanced in comparison with the unreinforced polypropylene. The hybrid reinforced composite composition containing FA and FP in ratio 3:1, had the best tensile, flexural, and hardness properties of all composites produced, ascribed to the achievement of a more uniform dispersion of FA/FP and stronger interface bonding with the polymer matrix. Specifically, enhancement of tensile and flexural strengths of 58.7% and 62.9%, respectively in comparison with the unreinforced propylene was obtained for this composition. The friction coefficient of the single reinforced composite compositions of FA and FP were higher compared to the hybrid reinforced composites and unreinforced polypropylene. The representative morphological assessments of the composites fracture surface showed that the single reinforced composite was characterized with the agglomeration of fiber ash/fiber particulates while the hybrid reinforced composites had relatively uniform distribution of reinforcement in the matrix. (paper)