Immobilization fo Azo-initiator and Subsequent Graft Polymerization of Vinyl Monomers on Cellulose Acetate

Abstract

Cellulose acetate azo-initiator (CAI) was prepared by treating celluose acetate (CAc) with 4, 4'-azobis (4-cyanovaleric acid) (ACVA) in pyridine under the existence of p-toluenesufonyl chloride (TsCI). The degree of substitution (DS) by azo group leveled off with TsCI concentration over 1mol/L and with ACVA concentration over 0.1mol/L for CAc concentration of 0.38mol/L. The reaction was completed within 30min. Vinyl monomers such as styrene (ST) and methyl methacrylate (MMA) were easily polymerized by CAI to prepare the graft copolymers. The rate of polymerization and grafting of MMA were larger than those of ST. Increase in DS by azo group led to incresse in conversion and grafting of monomers. Grafting efficiency of monomers and apparent initiator efficiency (ATE) were 40_??_50% and 0.7_??_1.9%, respectively.