Efficient Graft Copolymerization of 2-Methyl-2-oxazoline onto Tosyl- and Iodo-Chitins in Solution

Abstract

Graft copolymerization of 2-methyl-2-oxazoline onto tosyl- and iodo-chitins has been examined. The reaction proceeded efficiently with tosyl-chitin in solution to give chitin derivatives having poly(N-acetylethyleneimine) side chains, and the grafting percentage was 280% under appropriate conditions. Graft copolymerization was also possible with iodo-chitin, but rather sluggish. Hydrolytic degradation of the chitin main chain allowed the isolation of the introduced side chains. The number-average molecular weight of the polyethyleneimine isolated from a graft copolymer with grafting percentage of 160% was 2700, indicating that 18% of the carbon atoms having a tosyloxy group were actually utilized for initiating the graft copolymerization. The resulting graft copolymers showed high affinity for both organic solvents and water, and may be useful as a new type of chitin-derived hybrid materials.