聚氨酯/聚丙烯酸酯复合乳液胶束的粒径及形态

以水性聚氨酯PU为种子,加入丙烯酸酯单体进行无皂乳液聚合,合成了聚氨酯/聚丙烯酸酯(PUA)复合乳液.动态激光光散射的测试结果表明,PU分散液和PUA复合乳液的粒径大小,与聚氨酯制备过程中的亲水性扩链剂的用量有密切关系.当扩链剂用量为7.5%时, PU/PA配比对PUA复合乳液粒子的粒径大小及分布影响不大,但是PUA复合乳液的平均粒径比纯PU乳液的粒子粒径显著增大,说明形成了核壳结构.并用透射电镜进行了证实.

STUDIES ON THE DIAMETER OF MICELLE OF PUA HYBRID EMULSIONS

Polyurethane/Polyacrylate(PUA) hybrid latexes were prepared by seeded surfactant-free emulsion polymerization, the polyurethane aqueous dispersions were used as seed particles. The diameter of micelle of aqueous PU dispersions and PUA composite latexes was measured by dynamic light scattering method. The results show that the diameter of the micelle greatly depends on the amounts of the hydrophilic chain-extender on the preparation of polyurethane ; when the hydrophilic chain-extender is (7.5%), the PU/PA mass ratios have not too much influence on the diameter of micelle of PUA composite latexes; and when the hydrophilic chain-extender is (7.5%), the synthesized PUA hybrid emulsions were found to form inverted core-shell structure with polyacrylate as the core and with polyurethane as the shell using transmission electron microscopy.