Effect of Caprolactam Modified Phenoxy-based Sizing Material on Reactive Process of Carbon Fiber-Reinforced Thermoplastic Polyamide-6

Abstract In spite of its short cycle time, the reactive process is hardly utilized to produce carbon fiber-reinforced thermoplastics (CFRTPs) due to relatively poor interfacial interactions between the carbon fiber and thermoplastic. To improve the mechanical strength of PA-6 CFRTP produced by reactive process, a caprolactam modified phenoxy-based sizing material was prepared. The sizing material acted as an initiator during reactive process, so the PA-6 chemically grown from the sizing material can entangled with the matrix, forming mechanically interlocking. Herein, carbon fiber coated by the sizing material was analyzed to determine the optimal coating conditions. The PA-6 CFRTP was also investigated in terms of impregnation, PA-6 matrix, and mechanical strength and the results were compared with PA-6 CFRTP produced with as-received and other phenoxy-based sizing material coated carbon fiber. Despite the reduced sizing material usage, it was surprisingly effective for increasing mechanical strength (by ∼68.8%) compared to neat CFRTP.