Ceric ion‐reducing agent redox initiated vinyl polymerisation

Ceric perchlorate/formaldehyde (F)redox couple initiated polymerisation of the monomer methyl acrylate (MA), acrylonitrile (AN), and methyl methacrylate (MMA) in perchloric acid (25°C) was carried out. The rate of polymerisation was directly proportional to [M]2 and [F] for all the systems. The rate was independent of [Ce4+] for the systems with MA or AN, but inversely proportional to [Ce4+] with MMA as the monomer. The rate of ceric disappearance was directly proportional to [Ce4+], [F], and [M]. The results were explained by a kinetic scheme involving the oxidation of the substrate by Ce4+ to give the primary radical and further reaction of the latter with Ce4+ to give the final product, and initiation of polymerisation both by Ce4+ and the primary radical, propagation followed by termination by the metal ion. Only with MMA as the monomer, the initiation by Ce4+ was found to be negligible compared to that by primary radicals. In the system with the reducing agents t‐butanol and n‐butanol, there was found to be 1:1 complex formation between the substrate and Ce4+. Otherwise the scheme is similar to that proposed for the Ce4+/HCHO/HClO4/AN (MA) systems.