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从分子设计的角度出发 ,以二苯甲烷 4 ,4′ 二异氰酸酯、二羟甲基丙酸、1,4 丁二醇、异佛尔酮二异氰酸酯、乙二胺和聚酯多元醇为原料 ,采用分步法制备了具有不同硬段结构、室温贮存稳定的聚氨酯水分散液。结果表明 ,随着硬段质量分数的增加 ,聚氨酯水分散液的粒径减小 ,但粒径分布不变。在聚氨酯水分散液成膜后的表面上 ,水的接触角增大 ,膜的吸水率显著降低。硬段质量分数为 5 0 %的聚氨酯水分散液成膜后表现出优异的耐水性能
From the molecular design point of view, diphenylmethane 4, 4 ’diisocyanate, dimethylolpropionic acid, 1,4 butanediol, isophorone diisocyanate, ethylenediamine and polyester polyols as raw materials, The polyurethane aqueous dispersion with different hard segment structure and stable storage at room temperature was prepared by the stepwise method. The results show that with the increase of hard segment mass fraction, the particle size of aqueous polyurethane dispersion decreases, but the particle size distribution does not change. On the surface of the polyurethane aqueous dispersion film after film formation, the contact angle of water increases, and the water absorption of the film decreases significantly. Hard segment mass fraction of 50% polyurethane aqueous dispersion showed excellent water resistance after filming