Portal de Periódicos da CAPES

Ceric ion‐reducing agent redox initiated vinyl polymerisation

1968; Wiley; Volume: 112; Issue: 1 Linguagem: Inglês

10.1002/macp.1968.021120101

0025-116X

S. V. Subramanian, M. Santappa,

Inorganic and Organometallic Chemistry

Abstract 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 [Ce 4+ ] for the systems with MA or AN, but inversely proportional to [Ce 4+ ] with MMA as the monomer. The rate of ceric disappearance was directly proportional to [Ce 4+ ], [F], and [M]. The results were explained by a kinetic scheme involving the oxidation of the substrate by Ce 4+ to give the primary radical and further reaction of the latter with Ce 4+ to give the final product, and initiation of polymerisation both by Ce 4+ and the primary radical, propagation followed by termination by the metal ion. Only with MMA as the monomer, the initiation by Ce 4+ 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 Ce 4+ . Otherwise the scheme is similar to that proposed for the Ce 4+ /HCHO/HClO 4 /AN (MA) systems.