聚醚多元醇和醇类扩链交联剂并用对聚氨酯弹性体性能的影响

用4,4′-二苯基甲烷二异氰酸酯（MDI）和聚四氢呋喃聚醚(PTMG)为原料合成聚氨酯（PU）预聚体，以三官能度聚醚多元醇（330N），三羟基甲基丙烷（TMP）和1,4-丁二醇（BDO）为原料制备PU弹性体。讨论了聚醚多元醇与醇类扩链剂并用和醇类扩链交联剂并用对PU弹性体性能的影响。结果表明，随着330N与BDO羟基数比增大，软段玻璃化转变温度（T_gs）随之降低、拉伸强度和硬度下降、拉断伸长率增加；而随着TMP与BDO羟基数比增加，T_gs随之升高、拉伸强度与拉断伸长率下降、硬度保持不变。

The effect of polyether polyols, alcohol chain extenders and crosslinkers on the properties of polyurethane elastomers

A polyurethane(PU) prepolymer has been synthesized from 4,4′-diphenylmethane diisocyanate(MDI) and polytetramethylene ether glycol(PTMG).PU elastomers were prepared by mixing the prepolymer with 1,4-butanediol(BDO) or the trifunctional polyether polyol(330N) as chain extenders or trimethylolpropane(TMP) as crosslinker.The effects of using a mixture of 330N and BDO chain extenders,and of using a mixture of BDO chain extender and TMP crosslinker on the properties of the PU elastomers were studied.When the 330N to BDO hydroxyl group ratio was increased the surface glass transition temperature(Tgs) and tensile strength decreased,whilst the elongation at break and hardness increased.When the TMP to BDO hydroxyl group ratio was increased,the values of Tgs increased,whilst the tensile strength and elongation at break decreased,and the hardness remained unchanged.