环氧改性水性聚氨酯涂料的合成与性能研究

采用环氧树脂与聚醚、二羟甲基丙酸（DMPA）和甲苯二异氰酸酯（TDI）反应制备水性聚氨酯涂料。研究发现随着所用的环氧树脂的环氧值的降低，改性水性聚氨酯涂膜的硬度和拉伸强度逐渐提高，断裂伸长率则随着降低。选用环氧值为0．44的环氧树脂所合成的改性水性聚氨酯的涂膜硬度达到玻璃硬度0．70；随着环氧树脂添加量增大，涂膜机械性能增加。采用后添加环氧树脂的合成工艺，可制备贮存稳定的水性聚氨酯乳液；凝胶渗透色谱（GPC）分析表明环氧树脂改性水性聚氨酯提高了聚氨酯的分子量。性能测试表明环氧改性水性聚氨酯涂料具有涂膜硬度高、耐水性好和耐溶剂性好等优点。

Study on Syntheses and Properties of Water-borne Coating of Polyurethane Modified by Epoxy Resin

The water-borne coating of polyurethane(WPU) was prepared by the reaction of epoxy resin with polyepoxyglcol, dimethoxypropionic acid and toluene diisocyanate (TDI). It was found that the hardness and tensile strength of coating film of WPU increased with decreasing in epoxy value of epoxy resin, and the elongation at break decreased with decreasing in epoxy value of epoxy resin. When the epoxy value of epoxy resin was chosen to be 0.44, the hardness of 0.7 for coating film of modified WPU can be attained. The mechanical properties of coating film of modified WPU increase with increasing the amount of epoxy resin. The storage stability of modified WPU is good as using the post-addition technology to add epoxy resin. The GPC measuring found that the molecular weight of WPU modified by epoxy resin is higher than that of traditional WPU. The properties testing showed that the waterborne polyurethane modified by epoxy resin has high hardness, good water resistance, resistance to petrol, and excellent adhesive to based material.