Radiation‐initiated graft copolymerization of acrylic acid and vinyl acetate onto LDPE films in two individual steps

Abstract

AbstractRadiation‐induced grafting of vinyl acetate (VAc) and acrylic acid (AAc) onto low‐density polyethylene (LDPE) films was carried out in two individual steps: initially, the polymer substrate was grafted either with VAc or AAc and the grafted film thus obtained was grafted with the other monomer. The graft copolymerization of AAc onto LDPE‐g‐PVAc films was enhanced when the content of PVAc is low. This is due to the high polarity and hydrophilicity of AAc. On the other hand, the grafting of VAc onto LDPE‐g‐PAAc films was restricted due to the difficulties of VAc diffusion through the crosslinked grafted chains of PAAc. The influence of inhibitor and monomer concentration on the degree of grafting was studied. The addition of 2wt% of Mohr's salt effectively reduced the homopolymerization of monomer during the irradiation process. The dependence of the grafting rate upon VAc concentration was found to be of 1.5 order. Some selected properties of the graft copolymers, swelling behaviour and electrical properties, were investigated.