硬段对热塑性聚氨酯弹性体结构及性能的影响

以实验室自制聚己二酸乙二醇酯二醇PEA为软段,二苯基甲烷-4,4’二异氰酸酯(MDI)为硬段,分别采用乙二醇(EG、1,4-丁二醇)、BOD和1,6-己二醇、HG为扩链剂,经预聚体法合成了硬段不同的聚氨酯弹性体。研究了硬段结构和硬段含量对弹性体硬度及力学性能的影响。采用旋转流变仪研究了弹性体在降温条件下的非等温结晶过程。结果表明,当硬段含量相同时,BDO-TPU结晶性能最好,拉伸强度最大;HG-TPU断裂伸长率最好。在BDO-TPU体系中,随硬段含量增加,材料硬度和强度增加,伸长率减小;结晶起始温度逐渐增大,结晶性能增强。

Effect of hard segment on structure and properties of thermoplastic polyurethane elastomer

The series of polyurethane elastomers were synthesized from polyol PEA which was synthesized in our lab, MDI and different chain extenders EG/BDO/HG, using prepolymer method. The effects of different hard segment on the properties of the elastomer were studied： The hardness and mechanical property were analyzed; The crystallization property were studied by means of rotary rheometer. The results showed that, under the same hard segment content, the BDO - TPU had the best crystallization and tensile strength; the HG - TPU had the best elongation at break. In the BDO - TPU system, with the increase of the hard segment content, the hardness and tensile strength increased, the elongation at break descended; both the onset temperature of crystallization and the crystallinity of TPE increased gradually.