Reinforcing nylon 6 via surface-initiated anionic ring-opening polymerization from stacked-cup carbon nanofibers

This article reports the preparation of nylon 6/stacked-cup carbon nanofiber (CNF) nanocomposites via in situ anionic ring-opening polymerization partially initiated from caprolactam-functionalized CNFs. As a result of the successful functionalization of CNF surface, good dispersion of the CNFs was observed by transmission electron microscopy (TEM). Moreover, with the addition of a very small amount of CNFs, significant enhancements in tensile modulus and yield strength were achieved together with slightly improved impact resistance. The enhanced stiffness may be attributed to effective filler-matrix stress transfer induced by interfacial covalent bonds. On the other hand, SEM micrographs provided evidence for the possible unraveling of the stacked-cup CNF, which may allow the CNFs to bridge the matrix during crack propagation, hence resulting in the toughening of the nanocomposites. (C) 2013 Elsevier Ltd. All rights reserved.