Graft copolymerization of acrylonitrile and acrylonitrile‐styrene onto carbon fibers containing unsaturated groups

Abstract Graft copolymerization of acrylonitrile and acrylonitrile‐styrene onto carbon fibers containing unsaturated groups was studied. Graft copolymerization of acrylonitrile was found to result in a very low grafting yield in comparison with styrene, and it remained nearly constant in the latter stage of the reaction. The effects of monomer concentrations, initiators, solvents, and reaction temperature on the monomer reactivity ratios were studied by using Hayes's equation to calculate the reactivity ratio. For graft copolymerization of acrylonitrile‐styrene were studied the rate of graft polymerization and the grafting yield with varying monomer compositions, both of which were found to be very low in the range of monomer compositions containing acrylonitrile at a level more than 8%. The monomer reactivity ratios for each monomer were calculated by use of the Fineman‐Ross method after the analytical determination of compositions of both grafted copolymer and ungrafted copolymer, and it was found that the monomer reactivity ratios for the grafted copolymer were very different from those for the ungrafted copolymer.