Tensile properties of discontinuous carbon fiber reinforced polypropylene modified by maleic acid

Discontinuous carbon fiber reinforced polypropylenes (CFRPP) have been expected to be recycling, light weight and good mechanical materials. It is known that the interfacial properties between polypropylene (PP) and carbon fiber (CF) are low. In this study, discontinuous CF reinforced PPs modified by maleic anhydride (CFRMAPPs) were made by injection molding. Tensile properties, fiber length distributions, and fiber orientation distributions of the CFRPPs were measured by multi-stage sampling and XRD methods. The tensile strength and modulus of the CFRMAPPs were higher than CF reinforced homo PP. The correlation between tensile properties and fiber length was not be observed. The correlation between tensile properties and crystallinities of PPs was not observed. The fiber orientation parameters of the CFRMAPPs were almost similar to those of CF reinforced homo PP. On the other hand, the tensile strength increased along with acid content in the PP increasing. Therefore, it was considered that the tensile strength increasing caused by the bonding between CF and PP by maleic anhydride.