Tensile Behavior of Polypropylene Reinforced with Comminutes Extracted from Out-of-Condition Aerospace Grade Carbon Fiber Prepreg Waste

Abstract

Carbon fiber reinforced thermoplastics are in demand for high performance composites, particularly for the aircraft industry. Waste disposal of carbon fiber in the form of off-cuts, out of life of prepreg and end-of-life components lead to the environmental pollution. This study focuses on the processing and characterization of carbon fiber prepreg comminutes reinforced polypropylene (PP) produced by melt compounding using an internal mixer. In this study, end-of-life carbon fiber prepreg were crushed into fine fibers and dried in oven at 220°C for one hour. It was divided into two types; (1) partially cured carbon fiber prepreg (c-CFP) and, (2) fully cured carbon fiber prepreg (c-CF). The composites were prepared by melt compounding in a Haake internal mixer at 180°C, 50 rpm for 10 minutes. Samples were tested for tensile properties (ASTM D638) and the morphology of fractured surface was observed using Scanning Electron Microscopy (SEM). Increasing carbon fiber in polypropylene was found to increase the Young’s modulus of the composites, but decreased the tensile strength. However, the tensile strength of composites with c-CFP were observed to surpass the neat PP at every loading level. Whereas for composites with c-CF the tensile strength was comparable to the neat PP only within the range of 3 – 5 wt.%.