Effect of wood filler on the mechanical and thermal behavior of polypropylene/short glass/short carbon fiber-reinforced hybrid composites

The current study focuses on the fabrication of polypropylene-based hybrid thermoplastic composites and evaluates the impact of wood filler addition on the mechanical and thermal characteristics of the developed composites. The composites are produced using a melt mix procedure which includes twin screw extrusion and injection molding. The individual impact of short glass fibers, short carbon fibers, wood filler and their hybridization effect on the mechanical and thermal behavior of the fabricated composites are examined at room temperature. Hybrid composites reinforced with short glass fibers and short carbon fibers exhibit better mechanical performance out of all the composites evaluated. Addition of wood filler deteriorates the tensile and flexural behavior of the composites; however, the impact strength of the composites is found to be increasing with increase in wood filler content. Hardness of the composites is found to be increasing with addition of wood filler as compared to neat polypropylene; however, the impact of wood filler addition with hybrid composites is found to be negligible. Among the composites evaluated, polypropylene reinforced with short glass and carbon fibers exhibited better hardness. Due to the synergistic impact of hybrid fibers and wood filler, the thermal stability of hybrid thermoplastic composite is reduced. It is evident from the morphological study of the fractured surfaces of the composites through scanning electron microscope (SEM) images that the fiber pullout, fiber fracture and agglomeration are the reasons for the failure of composite materials.