Homogeneous Graft Copolymerization of Vinyl Monomers onto Cellulose in a Dimethyl Sulfoxide– Paraformaldehyde Solvent System. I. Acrylonitrile and Methyl Methacrylate

Abstract

Homogeneous graft copolymerization of acrylonitrile (AN) and of methyl methacrylate (MMA) onto cellulose was carried out in a dimethyl sulfoxide–paraformaldehyde solvent system. Ammonium persulfate (APS) and azobisisobutyronitrile (AIBN) were used as radical initiators. The optimum grafting condition for each monomer–initiator system was determined from experiments in which temperature and concentrations of initiator, monomer, and cellulose were varied. The grafting yield for the AN–APS system was higher than that for the MMA–APS system. The grafting onto cellulose hardly proceeded in the AN–AIBN system, but appreciably in the MMA–AIBN system. The grafting of MMA proceeded similarly either with AIBN or APS as the initiator. It was found that the chain transfer from PMMA homopolymer radicals to backbone cellulose occurred. The number of grafts per cellulose chain was found to be in the range from 0.5 to 3.9.