新型热塑性聚氨酯弹性体粘合剂的合成与表征

Synthesis and Characterization of Novel Thermoplastic Polyurethane as Thermoplastic Elastomer Propellant Binder

以聚己二酸乙二醇酯低聚物二元醇为软段、异佛尔酮二异氰酸酯和 1 ,4-丁二醇为硬段 ,采用熔融预聚二步法合成了一种可为硝酸酯增塑并满足推进剂使用要求的热塑性聚氨酯弹性体 (TPU)。确定了合成反应温度、反应时间以及 R值 ,并采用 GPC、FTIR、力学性能测试、硝化甘油吸收实验等分析测试技术对 TPU进行了表征。结果表明 ,在所选择的硬段含量范围内 ,TPU均具有合理的数均相对分子量和线性聚酯聚氨酯的结构特征 ,以及与硝酸酯良好的相容性 ,当硬段含量为 50 %～ 55%时 ,热塑性聚酯聚氨酯弹性体具有满足推进剂使用要求的力学性能 (σm>3MPa,εm>50 0 % )

A novel thermoplastic polyurethane elastomer based on polyethylene adipate as soft segments , isophorone diisocyanate and 1,4butanediol as hard segments is synthesized for the purpose of using as propellant binder. A series of thermoplastic polyurethanes with different hard segment contents are synthesized by meltprepolymerization method. Reaction temperature, reaction time, and R value are determined. GPC, FTIR, tensile test and the miscibility with nitrate ester are applied to make further characterization of the TPU. Measured results show that the TPU with 50%～55% fraction of hard segment exhibits excellent integrate properties to meet requirements of propellant in terms of good miscibility with nitrate ester and mechanical properties (σ m>3 MPa,ε m>500%).