摘要： 以聚四氢呋喃醚与聚环氧丙烷醚为柔性链段合成水性光固化聚氨酯,并制备乳液。研究了聚醚软段和小分子扩链剂的类型对乳液和涂膜性能的影响,以及固化时间、光引发剂的添加量对涂膜硬度的影响。采用红外光谱(FT-IR)对树脂的结构进行表征,并采用动态光散射法(DLS)对乳液的粒径进行分析。结果表明:乳液平均粒径<65 nm;乳液经高温稳定测试、离心测试、冻融测试和稀释测试后絮凝率均<2.6%,具有很好的稳定性;实验所得乳液在木材表面涂覆,基材光泽稍有提高;涂膜耐冲击性>50 cm,附着力为1级,铅笔硬度达到5H。

关键词: UV固化, 水性聚氨酯, 高硬度, 玻璃涂层, 木材底涂

Abstract: The title waterborne UV curable polyurethanes were synthesized with polytetrahydrofuran ether and poly ( propylene oxide) ether as soft segments and their emulsions were prepared. Effects of soft segments and small molecular chain extenders on properties of emulsions and coatings and influence of curing time and photoinitiator on coating's hardness were investigated. Molecular structure was characterized by Fourier transform infrared(FT-IR)spectra and emulsion particle size was measured by dynamic light scattering (DLS). It was indicated that the average particle sizes of emulsions were less than 65 nm, the obtained emulsions showed good stability. The calculated gel percentage after high temperature aging test centrifugation test, freezing-thaw test and dilution test were less than 2.6%. Coatings on wood substrates had a gloss 1 higher than original substrate. Their impact strength was larger than 50cm and adhesion grade 1, and pencil hardness upto 5H.

Key words: UV curing, waterborne polyurethane, high hardness, glass coating, wood primer