Effects of carbon nanofibers on carbon fiber reinforced thermoplastics made with in situ polymerizable polyamide 6

Abstract The effects of carbon nanofibers (CNFs) on the mechanical properties of carbon fiber reinforced thermoplastics (CFRTPs) made with in situ polymerizable polyamide 6 (PA6), which are derived through the polymerization of e-caprolactam, were discussed. Although it is difficult to disperse CNFs in solvents, including molten polymers, e-caprolactam was successfully obtained with good CNF dispersibility. CFRTPs with good dispersion of CNFs were molded while maintaining moldability below the CNF weight fraction of 0.5 wt%. Furthermore, it was revealed that CNFs increased the molecular weight of PA6, and the elastic modulus of the matrix polymer increased. As a result, the stress transfer ability increased, and the bending properties of the CFRTPs, particularly the bending strength, also increased.