CARBON FIBER SIZING MATERIAL FOR THERMOPLASTIC POLYAMIDE-6 COMPOSITES PRODUCED BY REACTIVE PROCESSING

摘要

The carbon fiber-reinforced thermoplastic (CFRTP) is increasingly studied for aerospace and automotive industries because the CFRTP has high-strength with desired light-weight and also can be welded or recycled upon melting. However, application of the CFRTP was still limited due to poor interfacial adhesion between carbon fiber and thermoplastics and long cycle time coming from high viscosity of thermoplastic. In this work, in order to improve mechanical strength of the CFRTP, the sizing material for PA-6 was designed. The sizing material can act as an initiator of polymerization during reactive processing, which form strong interfacial adhesion. Also the PA-6 CFRTP were produced by reactive processing with in-situ polymerization of caprolactam, of which has low viscosity. So that the CFRTP having good impregnation can be produced with short cycle time. The produced CFRTP were investigated in terms of PA-6 matrix, impregnation, interfacial adhesion, and mechanical strength, especially inter-laminar shear strength (ILSS). As a result, in despite of tiny amount of the sizing material usage, the sizing material is surprisingly effective to increase ILSS more than 30 % comparing with the neat CFRTP.