尿素对水性聚氨酯性能的影响

以异佛尔酮二异氰酸酯（IPDI）、聚醚220、聚酯二元醇为主要原料，二羟甲基丙酸（DMPA）为亲水性扩链剂，并分别用乙二胺和尿素作扩链剂，合成阴离子型水性聚氨酯乳液。对比2种扩链剂对水性聚氨酯乳液黏度、膜吸水性及玻璃化转变温度（Tg）的影响.结果表明，增加乙二胺的用量，能提高聚氨酯乳液黏度，降低其膜的吸水性，增大聚合物Tg．而增加尿素的用量对聚氨酯乳液黏度和聚合物Tg没有明显影响，但提高了膜吸水性。说明尿素没有起到扩链作用，但可以作为封端剂在聚氨酯分子末端引入胺基。

Influence of urea on properties of waterborne polyurethane

Using IPDI,N220,polyester diol and DMPA as main raw materials and EDA and urea as chain extender,the anionic water-based polyurethane(WPU) emulsion adhesive was synthesized.The influences of the chain extender on emulsion viscosity,water absorption rate and glass transition temperature of WPU film were studied.The results showed that the emulsion viscosity increased,the water absorption rate of WPU film decreased at first and then increased with increase of the amount of EDA.In contrast,there was no signifi...