Gamma Ray-Induced Graft Copolymerization of Styrene onto Bleached Jute Yarn

Abstract

Polystyrene was grafted onto bleached jute yarn by irradiation of jute-styrene mix tures with Co⁶⁰ gamma rays under various conditions. No grafting occurred with styrene unless a jute swelling agent, such as water, methanol, ethanol, formic acid, acetic acid, dimethylformamide, or dimethylsulfoxide was added. For a fixed radiation dose and styrene-jute ratio, increasing amounts of water or any of the swelling agents increased the amount of polystyrene grafted to a maximum and then decreased it. With water as swelling agent, more polystyrene was grafted onto bleached jute than onto unbleached jute. With increasing radiation dose grafting increased slowly up to 2 megarads, and then increased approximately littearly with higher close. On heating the bleached-jute-styrene-water system after irradiation, further grafting occurred. The higher the radiation dose, the greater the resulting postirradiation graft ing on heating for a fixed time and temperature. Increase in radiation dose resulted in increased grafting, accompanied by increased twist, transverse swotting, and longitudinal shrinkage, and a sharp decrease in moisture regain. The tensile strength remained unaffected with 0.5-megarad exposure, increased with 1 megarad, and then decreased with higher doses.