PHOTOGRAFTING OF ACRYLONITRILE AND METHACRYLIC-ACID ON POLYETHYLENE FILM UNDER AIR ATMOSPHERE

Photografting of acrylonitrile (AN) and methacrylic acid (MAA) on low-density polyethylene film (thickness 70 mum), on which benzophenone was coated earlier, was investigated at 60-degrees-C in water medium under air atmosphere. In the case of AN monomer, where grafted polymer was formed predominantly, oxygen in the system promoted the formation of both grafted polymer and homopolymer. With MAA monomer, in which homopolymer was formed preferentially compared to the formation of grafted polymer, the formation of homopolymer was accelerated by the presence of oxygen while suppressing that of grafted polymer. The formation of polyethylene peroxides by photoirradiation seemed to be a factor for the accelerated polymerization under air atmosphere. It was found that additives such as hydrazine and metallic ions (Fe2+, Cu2+, and Ni2+) are useful for enhancing the photografting under air atmosphere.