封闭型水性多异氰酸酯固化剂的制备及其性能研究

Preparation and Characterization of Waterborne Blocked Polyisocyanate Curing Agents

利用甲乙酮肟（MEKO）与IPDI三聚体反应并接枝聚乙二醇单甲醚（MPEG）制备了封闭型水性多异氰酸酯固化剂，采用红外光谱仪、热失质量仪和透射电镜等设备研究了该固化剂的结构、解封温度及胶束形态，同时考察了固化剂对羟基型水性聚氨酯树脂的固化效果及其混合乳液的贮存稳定性。结果表明，该水性固化剂的解封温度在95～249℃之间，最佳使用温度在160℃左右；该固化剂可明显改善羟基型水性聚氨酯膜的耐水、耐溶剂及力学性能，另外固化剂与水性聚氨酯的共混乳液具有良好的贮存稳定性。

The title waterborne blocked polyisocyanate curing agents have been prepared by reaction of IPDI trimer with methyl ethyl ketoxime （MEKO） as blocking agents and then grafted with methoxy PEG （MPEG）. The structure, deblocking temperature and particle morphology of curing agents were characterized by FT - IR, TGA and TEM. The performances of crosslinked coating film and storage stability of mixture of hydroxyl aqueous polyurethane and curing agents were investigated. Results showed that deblocking temperature of curing agent range from 95 ℃ to 249 ℃. The best deblocking temperature for practical use is about 160 ℃. Water resistance, solvent resistance and mechanical properties of aqueous polyurethane coating film crosslinked by this curing agent has been improved significantly. Additionally, mixture of curing agents and hydroxyl aqueous polyurethane shows satisfied stability.