Grafting onto wool. XXV. Effect of acids on γ-radiation-induced graft copolymerization of methyl methacrylate onto wool fiber

Graft copolymerization of methyl methacrylate (MMA) onto Himachali wool fiber has been investigated in aqueous medium by using γ irradiation from a 2100 Ci⁶⁰CO source as means of initiation. Graft copolymerization was carried out by the mutual method in nitrogen atmosphere as well as in air. Effect of mineral acids and acetic acid on percentage of grafting was studied. Percentage of grafting was determined as functions of total dose, concentration of monomer, and concentration of acids. Maximum percentage of grafting in the presence of acids occurred in nitrogen atmosphere at a total dose of 1.05 MR. All the acids were found to influence grafting and the reactivity of different acids towards graft copolymerization was found to follow the order: H₂SO₄ > HCl > HNO₃ > HC1O₄ > HOAc. An attempt has been made to explain the reactivity order of different acids in the light of the mechanism proposed for γ-irradiation-induced graft copolymerization of vinyl monomer onto wool fiber.