通过单因素试验对聚氨酯改性明胶反应体系中异氰酸酯基(-NCO)质量分数的分析,优化了聚氨酯改性明胶的最佳条件:聚氨酯预聚体与明胶的质量比为7:6.改性温度为75℃,改性时间为3h.使用红外光谱和综合热分析仪分别对聚氨酯预聚体、明胶、聚氨酯改性明胶进行了结构表征和热稳定性分析.结果表明,聚氨酯已经接枝到明胶分子链上,而且聚氨酯改性明胶具有良好的热稳定性.通过对力学性能的分析,改性薄膜具有较好的抗张强度与伸长率.%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 °C ,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.
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