摘要： 以4,4′-二环己基甲烷二异氰酸酯(HMDI)和2,2-二羟甲基丙酸(DMPA)制备异氰酸酯封端的线性预聚体,以预聚体与三羟甲基丙烷(TMP)反应合成支化结构的中间体,再以DMPA对支化型中间体进行扩链,最后以咪唑(IDZ)、2-甲基咪唑(2-MI)和4-硝基咪唑(4-NI)分别对活性的—NCO基团进行封闭,制得一系列封闭型水性多异氰酸酯交联剂,并以傅里叶变换红外光谱(FT-IR)表征了交联剂的结构。研究了封闭剂的结构对交联剂解封温度的影响及交联剂的固化工艺对涂膜性能的影响。研究表明该系列交联剂的最低解封温度约为110℃,交联剂的最优固化工艺为160℃下固化30 min。

关键词: 封闭型, 水性, 多异氰酸酯, 交联剂

Abstract: The NCO-terminated linear prepolymer was synthesized by the reaction of 4, 4,-dicyclohexylmethane diisocyanate (HMDI) and 2, 2-bis( hydroxymethyl propionic acid (DMPA), which was further reacted with trimethylolpropane (TMP) to obtain branched intermediate. Then, DMPA was used as chain-exten agent to react with the branched intermediate. The residual active NCO groups were blocked with imidazole (IDZ), 2-methylimidazole (2-MI) and 4-nitroimidazole(4-NI) respectively, forming a series of blocked and waterborne polyisocyanate crosslinkers. FT-IR was used to characterize the structure of crosslinkers.The influence of the structure of blocking agents on deblocking temperature and the curing process on the properties of cured films were studied. The results indicated that the lowest deblocking temperature was 110 ℃ and the optimal curing process was at 160 ℃ for 30 min.

Key words: blocked, waterborne, polyisocyanate, crosslinker