用磺酸型亲水扩链剂制备高固含量聚氨酯乳液

卫晓利　 张发兴　

摘　要：以聚(四氢呋喃-co-氧化丙烯)二醇为软段、异佛尔酮二异氰酸酯为硬段,以1,2-二羟基-3-丙磺酸钠(DHPA)作为亲水扩链剂,用自乳化法合成了一系列稳定的高固含量聚氨酯乳液,分析了DHPA用量对乳液及其胶膜性能的影响.结果表明:所得聚氨酯乳液的粒径呈多元分布,乳胶粒子呈球形;乳液为假塑性流体;随着DHPA用量的增加,乳液平均粒径逐渐减小,粒径分布变窄,固含量不断增大,当DHPA质量分数为7%时,乳液的总固物质量分数可达61%.乳液具有较好的高、低温及贮存稳定性能.随着DHPA用量的增加,聚氨酯乳液胶膜的拉伸强度逐渐增大,扯断伸长率则先增大后减小;当DHPA质量分数为5%时胶膜的综合力学性能最佳;DHPA用量对胶膜的热稳定性没有明显影响.
关键词：磺酸型亲水扩链剂;聚氨酯乳液;高固含量;稳定性;力学性能
分类号：TQ334.1 　文献标识码：A
文章编号：1000-1255(2010)01-0029-04

Preparation of high solid polyurethane emulsion with sulfonate hydrophilic chain extender

Wei Xiaoli（Department of Science, North University of China, Taiyuan 030051, China）　 Zhang Faxing（Department of Material and Chemical Engineering, Sichuan Institute of Technology, Zigong 643000, China）　

Abstract：A series of novel stable polyurethane emulsion with high solid and low viscosity were prepared by self-emulsification, using poly(tetrahydrofuran-co-epoxy propane) glycol (Ng 210) as soft segment, isophorone diisocyanate(IPDI) as hard segment and 1,2-dihydroxy-3-propanesulfonic acid salt(DHPA) as hydrophilic chain extender. Influence of the amount of DHPA on properties of polyurethane emulsion and its film were discussed. The results showed that the obtained emulsion had polydispersibility in particle size and was spherical in particle shape. It is noticed that with increasing the amount of DHPA, the average particle size of the emulsion decreased, particle size distribusion became narrower and solid content increased. When the mass fraction of DHPA was 7%, solide mass fraction reached 61%. The high solid emulsion exhibited pseudo plastic behavior. In addition, polyurethane emulsion were endowed with good stability at high temperature and low temperature as well as the storage stability. When the mass fraction of DHPA was 5%, the polyurethane film exhibited better mechanical properties, and the amount of DHPA had no influence on thermal stability.
Keywords：sulfonate hydrophilic chain extender; polyurethane emulsion; high solid; stability; mechanical property