A waterborne polyurethane (WPU)was prepared by the reaction of γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH-560, as modifier) with poly (propylene carbonate) polyols (PPC), dimethylol propionic acid (DMPA) and isophorone diisocyanate (IPDI).The effects of modification reaction mechanism and KH-560 dosage on the properties of WPU emulsion and film were studied. Results showed that KH-560 mainly reacted with carboxyl groups in DMPA and most of the reaction occurred during the neutralization and film cast process. The use of modifier KH-560 significantly improved the water resistance of WPU and the maximum water absorption decreased by 500%. When the amount of KH-560 reached 2% by mass, after immerging in water for 5 days, the adhesion of the film to the glass still reached level 0. It was also found that after modification by KH-560, the hardness of the film increased,but the elongation at break and the tensile strength decreased to a certain extent.%以聚碳酸亚丙酯多元醇(PPC)、异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)为原料,制备水性聚氨酯乳液(WPU),采用γ-缩水甘油醚氧丙基三甲氧基硅烷(KH-560)对WPU进行改性.研究了改性反应机理、KH-560用量对WPU乳液、胶膜性能的影响.研究表明,KH-560主要在中和及成膜阶段与DMPA中羧基发生反应;改性后WPU胶膜的耐水性得到明显改善,吸水率最高下降500%,当KH-560用量达到质量分数2%时,水浸5天后,胶膜对玻璃的附着仍然达到0级;研究还发现,KH-560改性后,胶膜硬度有所提高,但是断裂伸长率和拉伸强度出现一定程度下降.
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