CONTRIBUTION TO THE MECHANISM OF CO-POLYMERIZATION OF PHENYLVINYL ALKYL ETHERS AND THIOETHERS WITH MALEIC-ANHYDRIDE

In the reported study, the equilibrium constants of the charge-transfer complex monomers of phenylvinyl alkyl ethers (I) and thioethers (II) with maleic anhydride (MAn) were determined by the transformed Benessi-Hildebrand NMR method, and it was found that the bulkiness of alkyl groups had no significant influence on the equilibrium constant. The rate of copolymerization, however, was largely dependent on the bulkiness of the alkyl groups in the phenylvinyl alkyl ether series. Spontaneous copolymerization did not occur, but I (R equals Et) copolymerizes with MAn in the presence of oxygen; II did not copolymerize with MAn in the presence of oxygen; nor in the presence of peroxide initiators. In the copolymerization of I (R equals Et) and MAn, it was found that molecular wieght increases with conversion. By applying the generalized model described by Shirota and co-workers, the reactivity ratios k//1//c/k//1//2 and k//2//c///2//1 for copolymerization of I (R equals Et) and II (R equals Et) with MAn were calculated from the change of copolymerization rate with monomer feed at constant total monomer concentration.