硬段对热塑性聚氨酯弹性体结构及性能的影响

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

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。

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.