酸型カルボキシメチルセルロースへの無触媒光グラフト重合

抄録

Non-catalytic and photo-induced graft copolymerization in single or binary monomer systems onto acid-form carboxymethyl cellulose (CMC-H) was studied. The graft copolymerization activity of monomers in the single system decreased in the order of methyl methacrylate (MMA)>acrylonitrile (AN)>styrene (St)>vinyl acetate (VAc). Increase of the monomer concentration resulted in higher degree of grafting and longer branched chains, but did not lead to increase in the apparent number of grafted chains. As degree of substitution of CMC was increased, degree of grafting and the apparent number of grafted chains increased. However, the branched chain length was constant or decreased. On the other hand, no polymerization occurred for the monomers without CMC. These results indicate that the graft copolymerization is initiated by the photolysis of carboxyl groups in CMC. The graft copolymerization with a binary monomer system (AN-MMA and AN-St) gave the monomer reactivity ratios of the ungrafted copolymers close to the reported values for homogeneous systems. The monomer reactivity ratios for the graft copolymers were smaller than those for the ungrafted copolymers; i.e., the alternating tendency for the former was higher than that for the latter.