Free radical graft polymerization of methyl methacrylate from polyvinyl alcohol using FeCl₃/K₂S₂O₅ redox pair

1414-1418Ferric chloride/potassium metabisulfite redox pair initiated free radical polymerization of methyl methacrylate has been carried out in aqueous medium both in presence and absence of polyvinyl alcohol (PVOH). The percentage of homopolymer formation is very low in absence of PVOH. However, the presence of PVOH (0.1%) gives rise to more than 70 % yield of polymethyl methacrylate homopolymer. About 60% graft copolymer (PVOH-g-PMMA) is achieved at 0⁰C using 1.0 % PVOH. Free radical polymerization (both homopolymer and graft copolymer) is decreased with the increase of temperature. Homopolymer formation and graft co-polymerization have been confirmed by FT-IR studies. A reaction scheme has been proposed to elucidate the role of ferric ion and metabisulfite ion