扩链剂用量对聚氨酯性能的影响

INFLUENCE ON PROPERTIES OF POLYURETHANE BY EXTENDER AMOUNT

本文采用聚四亚甲基醚二元醇和4,4’-二苯基甲烷二异氰酸酯进行逐步聚合反应,再分别用乙二醇、1,4-丁二醇、1,6-己二胺等扩链剂合成聚氨酯。小角激光散射的结果表明,在一定的扩链剂用量范围内,产物为亚微观无定形结构,且当扩链剂减少到一定程度之后向球晶演变。溶解测定结果表明,本文中的聚氨酯为具有不同支化程度的可溶性聚合物。

By reduce of extender amount, we have prepared polyurethane with branching points as a result of reaction of excessive-NCO groups and the hydrogen atoms of-NHCO groups in polyurethane chains. The percentage elongation of them is approximetal 1600%, which is 2-3 times high than that by ordinary synthetic method and the properties at lower temperature retain constant. Study of low angle laser light scattering indicats, in a certain limits of extender amount, the polyurethane have a amorph pseudomicrostructure and develops to spherocrystal under a extent of the reduce of extender amount. In addition to, the determination results of solubility indicat all polyurethane samples in this paper are soluble polymers with branching of different extent.