扩链剂种类和用量对高铁用聚氨酯减震垫成型及性能的影响

Effects of Kinds and Amount of Chain Extender on Molding and Properties of High-Speed Railway Shock

以4,4'-二苯基甲烷二异氰酸酯(MDI)、聚醚多元醇为主要原料,通过低压浇注机制备高铁用聚氨酯减震垫,考察了不同扩链剂种类及用量对聚氨酯高铁减震垫成型及性能的影响。结果表明,随着硬段含量的增加,聚合物的反应速度加快。高铁减震垫的拉伸强度、垂向静刚度增加,断裂伸长率减小,动静刚度比先减小后增大,耐低温性能下降,动态性能及耐热性能提高。随扩链剂分子链的增加,除1,3-丁二醇外,拉伸强度减小,断裂伸长率先增大后减小,耐油体积变化率增大,压缩永久变形减小,制品的静刚度增大,动静刚度比减小;耐低温性能改善。

High-speed railway polyurethane（PU） shock was prepared with 4,4＇-diphenylmethane diisocyanate（MDI） and polyether polyol.The effects of kinds and amount of chain extender on molding and properties of high-speed railway shock were investigated.The results show that with increase of the amount of chain extender,the reaction speed and the tensile strength,dynamic mechanical property,the heat resistance are increased,the elongation at break is decreased,the product property of static stiffness is increased,the dynamic-static stiffness ratio is increased first then decreased.In addition,with increase of the length of molecular chain of different kinds of chain extender,except for 1,3-butanediol,the material properties of tensile strength,oil resistance are decreased,the elongation is increased first and then decreased,the low temperature resistance and compression set are improved,the static stiffness rises up,the dynamic-static stiffness ratio is reduced.