HMDI-PTMEG基透明聚氨酯弹性体热老化机理研究

Study on Thermal Degradation Mechanism of Transparent Polyurethane Based on HMDI-PTMEG

以PTMEG,HMDI,1,4-BDO,TMP为原料,DBTDL为催化剂,按n(PTMEG)∶n(HMDI)∶n(1,4-BDO、TMP)=1∶3∶2的比例,采用两步法合成了透明聚氨酯弹性体,对弹性体进行150℃热老化试验,通过DSC,FTIR,13CNMR等手段对弹性体的热老化机理进行了研究,对FTIR,13CNMR的谱峰进行了归属。结果表明,热老化后弹性体的热力学性质发生了较大改变,醚键的氧化破坏是聚氨酯弹性体结构和性能发生变化的主要原因。

A series of transparent polyurethane elastomers based on HMDI,PTMEG,1,4-BDO and TMP were synthesized by two-step method,the ratio between n（PTMEG）,n（HMDI） and n（1,4-BDO,TMP） was 1∶3∶2 and the catalyst was DBTDL.Thermal ageing experiments had been carried out at 150℃.The mechanism of thermal degradation had been investigated by DSC,FTIR and 13CNMR.Spectrum of FTIR,13CNMR had also been attributed.It indicated that thermal and mechanical properties of the elastomer had greatly changed after aging.Oxidation of ether bonds was the main reason to cause the structure and property change.