INITIATION OF GRAFT-COPOLYMERIZATION BY DIRECT OXIDATION OF LIGNOCELLULOSE WITH KMNO4 AND ITS MECHANISM

The oxidation of bagasse pith, a lignocellulose material, with potassi um permanganate in dilute sulfuric acid solution creates active sites for grafting onto lignin and holocellulose. The grafted poly(methyl me thacrylate) chains on lignin and holocellulose were separated, respect ively, by delignification with sodium chlorite and hydrolysis of holoc ellulose with 72% sulfuric acid, and their molecular weights were meas ured. Lignin shows quite higher reactivity to grafting than does holoc ellulose. The roles of phenolic hydroxyl, alcoholic hydroxyl, and carb onyl groups of lignin are discussed by investigating the effect of pre treatments of lignocellulose on grafting, and a suitable grafting mech anism is proposed.