Improvement of dyeability of para-aramid fibers using electron-beam-induced graft polymerization

Abstract

The surface modification of a para-aramid fiber was investigated by graft polymerization of a vinyl monomer having an anionic group onto radicals on the fiber surface that were induced by electron beam (EB) irradiation. Generation of the radicals in the fiber irradiated with EB was evaluated, and it was determined that the radical concentration of the fibers increased with an increase in the dose of radiation. Acrylic acid (AA) was used as the anionic vinyl monomer for graft polymerization. Dyeability was improved for the fabrics that had been graft polymerized with AA because of the formation of ionic bonds between the anionic groups in the grafted chain and the cationic dyes. Furthermore, color fastness to washing was improved for the fabric graft copolymerized with AA and methyl acrylate (MA) compared to that for the fabric grafted with only AA, because the hydrophobic parts of MA in the grafted chains caused a hydrophobic interaction with the dye in addition to ionic bonding.