以聚四亚甲基醚二醇、4,4′-二苯基甲烷二异氰酸酯和 1,4-丁二醇为原料制备了 3 种软段分子量不同的聚醚基聚氨酯,研究了软段分子量对热塑性聚氨酯的微观结构和宏观性能的影响.采用红外光谱和小角 X 射线散射表征了材料的氢键作用和相结构;采用差示扫描量热法、动态热机械分析和拉伸物理方法表征了材料的热性能和力学性能;结合耗散粒子动力学(DPD)模拟,从另一方面说明了3 种热塑性聚氨酯材料的相结构.结果表明,随着所用聚醚分子量的增加,聚氨酯的微相分离程度增加,硬段之间的氢键作用更强,链段紧密排列聚集形成大尺寸的硬段相区;高分子量聚醚基聚氨酯的力学性能表现最好,具有更高的熔点,与模拟结果保持一致.
The Effect of Molecular Weight of PTMG on the Microphase Separation Structure and Mechanical Properties of TPU
Three types of polyether based polyurethanes with different soft segment molecular weight(MW)were prepared using polytetramethylene ether glycol,4,4′-diphenylmethane diisocyanate,and 1,4-butanediol as raw materials.The effects of soft segment MW on the microphase structure and macroscopic properties of thermoplastic polyurethane were studied.The hydrogen bonding and phase structure of the material were characterized by infrared spectroscopy and small angle X-ray scattering.The thermal and mechanical properties of the material were characterized using differential scanning calorimetry,dynamic thermomechanical analysis and stretching physical methods.Combined with the dissipative particle dynamics simulations,the phase structure of three types thermoplastic polyurethane were illustrated from another point of view.The results indicated that,as the MW of the soft segment of the polyether increased,the degree of microphase separation of polyurethane increased,the hydrogen bonding between the hard segments was stronger,and the tightly arranged chain segments formed a large-sized hard segment.The high polyether MW polyurethane had the best mechanical properties and higher melting point,which was consistent with the simulation results.
TPUmicrophase separationphase structurehydrogen bond
NETL
NSTL
万方数据
维普
