摘要： 为制备水性聚氨酯（ＷＰＵ）耐洗刷涂料，用硅烷偶联剂改性纳米 ＴｉＯ２，并采用预聚体分散、种子原位乳液聚合法分别制备了 ＴｉＯ２／ＰＵ、ＴｉＯ２／聚甲基丙烯酸甲酯（ＰＭＭＡ）／ＰＵ复合乳液。探讨了 ｎ（—ＮＣＯ）∶ｎ（—ＯＨ）（Ｒ值）、纳米 ＴｉＯ２加入方式与含量、ＭＭＡ／ＰＵ质量比及填料与功能助剂类型对 ＰＵ耐洗刷性能的影响。透射电镜形貌观察表明：ＴｉＯ２／ＰＭＭＡ／ＰＵ复合乳液乳胶粒子具有以 ＴｉＯ２为核的核壳结构。结果表明乳液种类对涂膜耐洗刷性影响较大，当纳米 ＴｉＯ２含量为 ０.５％、ＰＭＭＡ／ＰＵ质量比 １∶４时，多层核壳结构复合乳液的耐洗刷性最好，达６３５０次；选择片状结构、质地较硬的填料、微纤及防水助剂能显著提高 ＰＵ涂料耐洗刷性，优化配方可制备出耐洗刷性达１００００次以上 ＰＵ乳液涂料

关键词: 核壳结构, 纳米TiO₂/PMMA/PU粒子, 耐洗刷性

Abstract: In order to prepare washable WPU coating, two composite emulsions of TiO2,/PU and TiO2,/PMMA/PU were respectively synthesized by use of silane coupling agent modified nano TiO2 pre-polymer dispersion and in situ seed polymerization method. The factors that affect the washability of WPU were inves-tigated, such as nNco/nou ratio (R value) the adding processes and content of nano,, mass ratio of MMA/PU, the type of fillers and functional additives. TEM morphology observation showed that the latex particles of TiO2, /PMMA/PU composite emulsion were of core-shell structure with TiO2 as the core. The re-sults showed that the types of the emulsion had a strong impact washability of coatings. The washability of composite emulsion with multilayer core-shell structure was the best and up to 6, 350 times when nano-TiO2 content and PMMA/ PU ratio is respectively 0.5% and 1: 4, and the washability of PU coatings can be significantly improved by adding hard flake fillers, micro -fibers and waterproof additives. The washability of PU emulsion coatings could be up to 10,000 times by optimizing the formula.

Key words: core-shell structure, nano-TiO₂/PMMA/PU particles, washability