Role of molecular motions in polymer reactions. Part 3.—Free-radical copolymerization of methyl methacrylate with maleic anhydride and citraconic anhydride

Abstract

A kinetic study of the copolymerization of methyl methacrylate and either maleic anhydride or citraconic anhydride shows that the termination rate constant decreases with increasing anhydride content. The decrease is too great to be accounted for solely as a reduction in the number of rotatable links in the chain. In the citraconic anhydride copolymerization all the kinetic constants have been evaluated at 30°C and the propagation constants are (monomer A methyl methacrylate)k_paa 340 l. mole^–1 sec^–1, k_pab 11 l. mole^–1 sec^–1, k_pba 20 l. mole^–1 sec^–1, k_pbb 0 l. mole^–1 sec^–1. The termination rate constant decreases from 3.3 × 10⁷ l. mole^–1 sec^–1 in methyl methacrylate to about 9.0 × 10⁶ l. mole^–1 sec^–1 in an equimolar mixture of both monomers.