PTMG型热塑性聚氨酯弹性体的变温红外研究

Study on variable-temperature IR of PTMG-based thermoplastic polyurethane elastomer

以二苯基甲烷二异氰酸酯(MDI)、聚四氢呋喃醚二醇(PTMG)、1,4-丁二醇(BDO)为原料,无催化剂条件下制备了热塑性聚氨酯,通过红外光谱(FT-IR)、核磁共振谱(NMR)、凝胶渗透色谱(GPC)等方法表征了其结构。通过变温红外光谱研究了温度对聚氨酯中氨基甲酸酯及氢键的影响,结果发现,当温度升高时氢键开始解离,而温度降低时氢键又发生重组;当温度升高到130℃及以上时,氨基甲酸酯有极少量解离,温度降低时又重新形成氨基甲酸酯。热重分析结果表明,热塑性聚氨酯样品热稳定性较好。

Thermoplastic polyurethanes were prepared with diphenylmethane diisocyanate(MDI),polytetramethylene ether glycol(PTMG)and 1,4-butanediol(BDO)without catalysts.Their structures were characterized by fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance spectroscopy(NMR)and gel permeation chromatography(GPC).The effect of temperature on the urethane and hydrogen bonding in polyurethane was studied by variable-temperature infrared spectroscopy.It was found that hydrogen bonding begins to dissociate with increasing temperature,while the new hydrogen bonding reformed with decreasing temperature,and carbamate dissociates very little with temperature rising to 130℃and above,while carbamate reformed with decreasing temperature.Thermogravimetric analysis results showed that the thermoplastic polyurethane samples had good thermal stability.