不同软段结构对PUR–T性能影响研究

Effects of Soft Segments with Different Structures on Properties of PUR–T

采用4,4′–二苯基甲烷二异氰酸酯为硬段,聚ε–己内酯、聚四氢呋喃醚二醇、聚乙二醇为软段,1,4–丁二醇为扩链剂合成了不同软段结构的热塑性聚氨酯弹性体(PUR–T),并用傅立叶变换红外光谱仪对其结构进行了表征,讨论了不同软段结构、不同软段分子量、不同软段浓度等因素对PUR–T力学性能和热性能的影响。结果表明,合成的PUR–T即为本研究的目标产物;PUR–T软段分子量越小其力学性能越优异,但对其热稳定性影响不大;软段结构对PUR–T的性能影响显著,其中聚酯型PUR–T的力学性能优于聚醚型PUR–T,但热稳定性较聚醚型PUR–T差;随着软段浓度的增加,PUR–T的拉伸强度和撕裂强度都呈先提高后降低的趋势,当软段浓度为60%时达到最高,PUR–T的热稳定性随软段浓度的增加而升高。

Different structures of thermoplastic polyurethane elastomer（PUR-T） was synthesized with 4,4＇-diphenyl methane diisocyanate as hard segment, poly（ e -caprolactone）, polyethylene tetrahydrofuran ether glycol, polyethylene glycol as soft segments, 1,4-butanediol as chain extender.The structures were characterized by Fourier transform infrared spectrometer.The influences of soft segment structure, molecular weight and concentration on PUR-T mechanical properties and heat resistance were discussed.The results showed that the prepared PUR-T was the target product in this experiment.The lower the molecular weight of PUR-T soft segment, the more excellent the mechanical properties, but the effect on its thermal stability was little.The effect of soft segment structure on PUR-T performance was remarkable.The mechanical properties of polyester PUR-T type were better than those ofpolyether PUR-T type.While the thermal stability ofpolyether type PUR-T was better.With the increase of the concentration of soft segment, the tensile strength and tear strength increased first and then decreased, and they reached the highest point when soft segment concentration was 60%.The thermal stability of PUR-T increased with the increase of soft segment concentration.