Research of Interface of Carbon Fiber Reinforced PA6 by In-Situ Anionic Polymerization

High polymer active functional groups can be grafted on the surface of carbon fibers so as to adjust the interface effect between fibers in the composite material and resin and improve the performance of composite material, by controlling the structure of grafted high polymer, the interface layer with intended performance can be well designed. Heat treatment does not affect the fiber strength, the content of functional groups on the surface of the fibers reaches the max. value around 1h. There are no macromolecules polymerized and grafted on the surface of carbon fibers not subjected to isocyanate grafting treatment. Through isocyanate treatment after heat treatment, it can be obviously seen that the nylon molecules are grafted on the fiber surface. When no activating agent is added in the polymerized monomers, the resin grafting percent of fiber surface can reach 18.8%; when 0.003 activating agent (mole ratio of it to monomers) is added in the monomers, the grafting percent of PA6 on surface of carbon fibers is only 7.65%, this is the result of reactive competition on the interface between monomer matrix and fibers.