缩聚物/加聚物复合胶乳的制备科学Ⅱ.核壳结构聚氨酯-丙烯酸酯复合乳液的合成与表征

用合成的含羧基端羟基聚氨酯树脂，通过强外力乳化可形成稳定的水性聚氨酯乳液，与苯乙烯和丙烯酸丁酯等单体共聚，合成具有核壳结构的聚氨酯－丙烯酸酯接枝乳液，通过接枝乳液和共混乳液的性能差别对比，及DSC，FT－IR，粒径分析及力学性能测试分析表明，在聚氨酯－丙烯酸酯接枝乳液中，聚氨酯与丙烯酸酯发生部分交联形成稳定的核－壳结构，文中还对聚氨酯－丙烯酸酯接枝乳液的交联机理进行了研究。

THE SYNTHESIS AND CHARACTERIZATION OF POLYURETHANE-ACRYLIC GRAFT EMULSION

The OH-functional polyurethane resin was prepared by IPDI, diols and carboxylic acid fuctional diol DMPA. The polyurethane resin was formulated to have an OH/NCO (hydroxyl/isocyanate) ratio of 1.2~1.5, it will provide hydroxyl-terminated polymer and lower average molecular weight ( w=3500, n=1100). Upon neutralization of the acid groups, this oligomer was dispered in water by emulsifying mechanically by using anionic and nonionic emulsifiers to produce the polyurethane emulsion. The synthesis of polyurethane-acrylic graft emulsion with core-shell structure was reported. The polyurethane-acrylic blend emulsion was compared with the polyurethane-acrylic graft emulsion by DSC, FT-IR, particle size analysis, and mechanical property, ect. It shows that the graft emulsion particle morphology consists of a polyurethane-acrylic core surrounded by a acrylic shell. The intimate molecular mixing of graft polymers are also claims to result in a superior balance of properties compared to physical blends of polyurethane emulsions and acrylic emulsions. The cross-linking mechanism of polyurethane-acrylic graft emulsion was discussed and predicted.