Grafting Vinyl Monomers onto Chemically Modified Wool Fibers: Graft Copolymerization of Methyl Methacrylate onto Reduced Wool Fibers Using Acetylacetonate Complex of Manganese(III)

Abstract

The graft copolymerization of methyl methacrylate (MMA) onto reduced Indian Chokla wool fibers was studied in aqueous solution using the acetylacetonato complex of Mn(III) as the initiator. Perchloric acid was found to catalyze the reaction. The rate of grafting was investigated by varying the concentration of the monomer and the complex, acidity of the medium, the temperature, and the reaction medium. It is observed that the graft yield increases with increasing concentration of the chelate and acid and with increasing temperature. There is an increase in graft yield within a certain concentration range of the monomer, after which it falls. The grafting is considerably influenced by changing the solvent composition of the reaction medium. A comparative study reveals that oxidized and reduced wools are better substrates than untreated and other chemically modified wools. The effect of various monomers on graft yield is investigated. MMA is found to be a most active monomer compared to other vinyl monomers like methyl acrylate, ethyl acrylate, n-butyl acrylate, and acrylic acid. A suitable reaction scheme for grafting of MMA on reduced wool has been proposed and activation energy calculated from the Arrhenius plot.