Abstract: A NCO-terminated branched prepolymer was synthesized by the reaction of isophorone diisocyanate (IPDI) and triethanolamine (TEOA), then reacted with N-methyldiethanolamine (MDEA) or polyether glycol (PEG) as hydrophilic chain extender, finally reacted with dimethylpyrazole (DMPto block the residual -NCO groups to form a cationic waterborne blocked polyisocyanate crosslinker. Its structure was characterized by Fourier transform infrared spectrum(FT-IR). The effects of isocyanate index(R₁) of the prepolymer-ization reaction and the type of hydrophilic chain extender on the properties of the obtained crossliker were discussed. It was found that the type of hydrophilic chain extender has a significant influence on deblocking temperature of crosslinker. Thus, the crosslinker showed the optimal perfomance when the R₁ was 1. 9 and MDEA was used as hydrophilic chain extender.

Key words: cationic, waterborne, blocked polyisocyanate, crosslinker

摘要： 以异佛尔酮二异氰酸酯（IPDI）和三乙醇胺（TEOA）制备支化型异氰酸酯基（-NCO）封端的预聚体，分别以 Ｎ－甲基二乙醇胺（MDEA）和聚乙二醇（PEG）为亲水扩链剂，最后用二甲基吡唑（DMP）封闭剩余的-NCO基团得到阳离子水性封闭型聚异氰酸酯交联剂，并用傅里叶变换红外光谱（FT-IR）表征了交联剂的结构。 主要研究了预聚反应时异氰酸酯指数（R₁ 值）以及亲水扩链剂的种类对交联剂性能的影响。 研究表明：亲水扩链剂的种类对交联剂的解封温度有显著的影响，当以MDEA 为亲水扩链剂、R₁ 值为 1.9时，交联剂的性能达到最佳。

关键词: 阳离子, 水性, 封闭聚异氰酸酯, 交联剂