Radiation-induced grafting of N,N′-dimethylaminoethylmethacrylate onto chitosan films

Chitosan films were grafted with N,N ′-dimethylaminoethylmethacrylate using the ⁶⁰Co gamma irradiation method. The effect of solvent composition, monomer concentration, dose rate, and total dose on grafting was studied. The solvent composition has a marked effect on the degree of grafting. Maximum yield was obtained in the water-methanol (1 : 1) system. The percent grafting increased with monomer concentration and was found to be higher at a lower dose rate for a constant total dose of 0.216 Mrad. The tensile strength, crystallinity, and degree of swelling of grafted films decreased on increasing graft level. However, the graft copolymers showed improved thermal stability. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 869–877, 1997