Grafting onto Wool. XVIII. Graft Copolymerization of Methyl Methacrylate onto Wool Fiber in the Presence of Tertiary Butyl Hydroperoxide-Mineral Acid as Initiator

Abstract

Graft copolymerization of methyl methacrylate onto Himachali wool fiber has been studied in aqueous medium using tertiary butyl hydroperoxide (TBHP) in the presence of H₂SO₄, HNO₃, and HClO₄. The percentage of grafting and percent efficiency have been determined as functions of concentrations of TBHP, acid, monomer, time, and temperature. TBHP alone did not produce any graft within the temperature range 60 to 75°C. In the presence of mineral acids, graft copolymerization of MM A occurred readily, indicating that acids play an important role in the production of graft co-polymer of MMA onto wool. A free radical mechanism for the initiation of grafting has been suggested. The mineral acids were found to vary in their abilities to produce graft copolymer, and the following order of reactivity of different acids was observed: H₂SO₂ > HClO₄ > HNO₃.