硬段对聚碳酸酯二醇型水性聚氨酯性能的影响

Influences of hard chain segment on properties of polycarbonate diol type waterborne polyurethane

以聚碳酸酯二醇(PCDL)为软段、二羟甲基丙酸(DMPA)为亲水扩链剂、异佛尔酮二异氰酸酯(IPDI)和六亚甲基二异氰酸酯(HDI)为硬段,采用预聚体法合成了水性聚氨酯(WPU)。研究结果表明:随着n(HDI)∶n(IPDI)比例的增加,WPU的黏度、断裂伸长率增大,耐水性和耐乙醇性提高;当n(HDI)∶n(IPDI)=1.0∶1时,WPU的综合性能相对较好,其热稳定性和结晶性能得到明显改善。

With polycarbonate diol （PCDL） as soft chain segment, dihydroxymethyl propionic acid （DMPA） as hydrophilic chain extender, isophorone diisocyanate（IPDI） and hexamethylene diisoeyanate （HDI） as hard chain segments, a waterborne polyurethane （WPU） was synthesized by prepolymer method. The research results showed that the WPU＇ s viscosity, elongation at break, water resistance and ethanol resistance were increased with increasing molar ratio of n（HDI） ： n（IPDI）. The WPU had the relatively better combination property, and its thermal stability and crystallization property were obviously improved when molar ratio of n（HDI） ：n（IPDI） was 1.0： 1.