Synthesis and Characterization of Polyurethane Modifying Gelatin

Through single factor experiment,the mass fraction of isocyanate-terminated(-NCO) in the reaction system of polyurethane modifying gelatin was studied and the optimized conditions of polyurethane modifying gelatin were got:the mass ratio of polyurethane prepolymer and gelatin was 7∶6,the modifying temperature was 75 ℃,and the modifying time was 3 hours.The structure characterization and thermal stability of polyurethane prepolymer,gelatin and gelatin modified by polyurethane was analysed by infrared spectroscopy and thermal analyzer and the results showed that the polyurethane prepolymer was successfully grafted to the gelatin chain.And the gelatin modified by polyurethane had good thermal stability.Through the analysis of the mechanical properties,the modified films had good tensile strength and elongation.