纳米级水基聚氨酯微凝胶环氧硅氧烷交联成膜机理

将端基为可水解硅氧烷的聚氨酯羧基离子体分散于水中，获得水基聚氨酯分散体。硅氧烷水解缩合形成高度交联的纳米级水基聚氨酯微凝胶（20nm～250nm)。此聚氨酯微凝胶成膜后采用水溶性环氧硅氧烷进一步交联，获得高性能有机涂层。扫描电子显微镜研究了涂层的结构，在实验基础上论述了交联成膜机理。

FILM FORMING MECHANISM OF AQUEOUS POLYURETHANE MICROGEL WITH EPOXY SILANE AS CROSSLINKER

Dispersing silylate terminated polyurethane in water, the silane end groups of the polymer underwent hydrolysis followed by condensation to form a stable nanometer size aqueous polyurethane microgel. The microgel has a highly crosslinked core and a thin hydrophilic shell. It has a good film forming property due to its extremely fine particle size. However, the crosslinking hindered the inter particle diffusion of polymer molecules. A compacted particle film with poor mechanical properties was formed by drying the microgel. Hydrophilic domains were formed by fusing together the hydrophilic shells of the microgel particles and the domains could be crosslinked by adding epoxy silane before the film forming. The newly formed crosslinked regions made the microgel particles band together and a better mechanical film was formed.