Two-step Radical Grafting onto Polypropylene Fiber Initiated by Active Species Prepared through the Irradiation of Electron Beam

Abstract

Graft polymerization is one of the surface modification methods for organic solid. When organic solids are irradiated by electron beam (EB), activation sites can be generated in the polypropylene and monomer reacts at the active site to grafted chains. First-step polymerization proceeded during EB irradiation. And then, the fiber was heated at high pressure to promote second step grafting with high propagation rate. The generated chains have bimodal distribution in molecular weight and high molecular weight component gradually increased with polymerization pressure for second grafting. The molecular weight of grafted chains and their distribution are evaluated from those for the extracted solution polymers. Temperature dependence of grafting efficiency gave us thermodynamic parameters for the grafting polymerization.