热塑性聚酯弹性体TPEE的热性能研究

Study on thermal properties of thermoplastic polyester elastomer TPEE

为了研究热塑性聚酯弹性体(TPEE)的热性能,制备了不同聚四氢映喃(PTMG)添加量的TPEE样品,采用差示扫描量热仪(DSC)、热失重仪(TG)研究了PTMG添加量对TPEE熔点、熔融热、熔融结晶温度、熔融峰型和熔融结晶峰型等热性能参数的影响规律,不同PTMG添加量对TPEE的非等温结晶行为,不同PTMG添加量对TPEE弹性热稳定性的影响。研究表明,随着软段PTMG添加量的增加,TPEE共聚酯的熔点逐渐下降,熔融峰及熔融结晶峰逐渐变宽,TPEE的非等温结晶峰向低温方向移动,且半结晶周期变长,结晶速率下降。通过非等温结晶动力学研究确认了少量PTMG的引人改变了PBT分子链的结晶生长方式,降低了结晶速率常数;但PTMG添加量进一步增加,不会对结晶生长方式产生影响,仅降低结晶速率。TPEE熔点、熔融结晶温度与PTMG添加量成线性关系,且相关性较好。随着PTMG添加量的增加,TPEE的起始分解温度T,相差不大,但其最大降解速率对应的温度T_(max)呈逐步上升趋势,TPEE弹性体的热稳定性逐渐增强。

In order to study the thermal properties of TPEE,the effects of different polyether(PTMG)content on TPEE melting point,melting enthalpy,melting crystallization temperature,melting crystallization enthalpy,melt-ing crystallization peak type and their variation rules were studied by differential scanning calorimetry(DSC),and the non isothermal crystallization behavior of TPEE with different polyether content was studied.The results showed that with the increase of polyether soft segment content,the melting point of TPEE elastomer gradually decreased,the melting peak and crystallization exothermic peak gradually widened,the non isothermal crystallization peak of TPEE moved to low temperature,and the semi crystallization cycle became longer,and the crystallization rate de-creased.The non isothermal crystallization kinetics study confirmed that the introduction of a small amount of poly-ether changed the crystallization growth mode of PBT molecular chain and reduced the crystallization rate constant.However,the further increase of polyether content will not affect the crystallization growth mode,but only reduce the crystallization rate.The melting point,melting crystallization temperature has a linear relationship with PT-MG content,and the correlation is good.The effect of different polyether content on the thermal degradation of TPEE elastomer was studied by thermogravimetric analysis(TG).The results showed that with the increase of PTMG con-tent,the initial decomposition temperature T,of TPEE was similar,but the temperature Tmax corresponding to the maximum degradation rate showed a gradual upward trend,indicating that with the degradation reaction,the ther-mal stability of TPEE elastomer gradually increased,which may be related to the antioxidant content.