巯基点击反应制备双重固化的水性混杂涂料

Preparation of Waterborne Dual Curing Hybrid Coating via Thiol Based Click Reaction

通过可逆加成-断裂链转移自由基(RAFT)乳液聚合的方法合成了一系列具有不同烯丙基/环氧基物质的量比的水性混杂乳液,将此混杂乳液与巯基封端的聚氨酯水分散体复合可制得含烯丙基/环氧基/巯基三种活性基团的水性混杂涂料,采用傅里叶红外光谱(FT-IR)对RAFT乳液和固化膜的结构及混杂涂料的固化过程进行研究,并研究了固化膜的性能。研究表明可通过RAFT乳液聚合制得具有预想结构的聚合物乳液,不同的固化条件对固化膜的性能有很大影响,在光/热双重固化的条件下,通过巯基点击反应制备的涂膜铅笔硬度为6H,耐甲乙酮的擦拭次数为1 000次,凝胶量为83.96%,耐冲击性>50 cm。

A series of waterborne hybrid emulsion with different mole ratio of allyl/epoxy were prepared through the reversible addition - fragmentation chain transfer radical （RAFT） emulsion polymerization, which were then blended with thiol terminated water - based polyurethane dispersion to obtain the waterborne hybrids coatings which containing allyl/epoxy/thiol three active groups. The structures of the emulsions and cured films and the curing process of hybrid coatings were characterized by FT - IR, at the same time, the properties of cured films were studied. The results showed that the emulsions with expected structure could be prepared through the RAFT emulsion polymerization, and the properties of cured films varied with differ- ent curing condition. Under UV/thermo dual curing conditions, the gel content of cured films was 83.96%, the solvent -resistance（MEK） was 1 000 time, pencil hardness 6H, and impact strength was greater than 50 cm.