Abstract

In this work, large numbers of hydrophilic functional groups were introduced onto gelatin by grafting with N-vinyl pyrollidone monomer. The graft copolymerization reactions were carried out under nitrogen atmosphere using ammonium persulfate (APS) as an initiator. The graft copolymer was characterized by Fourier transform infrared spectra, thermo-gravimetric analysis and solubility test. The existence of a sharp intense peak at 1653 cm^-1 in FTIR spectra of the graft copolymer, improvement of the thermal stability of gelatin-based copolymer and the solubility difference of the copolymer and the homopolymer prove the formation of graft copolymer. The effects of reaction variables, such as concentration of the initiator, monomer and gelatin, as well as, reaction temperature and time were investigated and the grafting conditions were optimized. The optimum reaction conditions resulting in maximum grafting ratio and add-on value have been determined.

Key words: Gelatin, N-vinyl pyrollidone, graft copolymerization, ammonium persulfate.