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聚氨酯由于其广泛的用途一直备受关注。采用化学滴定方法,研究了异佛尔酮二异氰酸酯(IPDI)和聚氧化丙烯二醇(PPG)在有机锡催化剂作用下的聚合反应,考察了温度、催化剂品种对聚合反应的影响。结果显示,该类反应符合逐步聚合反应的二级动力学特征,在50~70℃下,二月桂酸二丁基锡为催化剂时体系的反应速率常数在1.36×10-2~6.10×10-2 kg.mol-1.min-1范围,活化能为69.12 kJ.mol-1;辛酸亚锡为催化剂时体系的反应速率常数在9.24×10-4~4.91×10-3 kg.mol-1.min-1之间,活化能为76.98 kJ.mol-1。实验表明,二月桂酸二丁基锡的催化活性远大于辛酸亚锡,是该类聚合反应的首选催化剂。
Polyurethanes have drawn much attention for their wide range of uses. The polymerization reaction of isophorone diisocyanate (IPDI) and polyoxypropylene diol (PPG) under the action of organic tin catalyst was studied by chemical titration method. The effects of temperature and catalyst variety on the polymerization reaction were investigated. The results show that this kind of reaction conforms to the second-order kinetic character of stepwise polymerization. The reaction rate constant of dibutyltin dilaurate is 1.36 × 10-2 ~ 6.10 × 10-2 kg at 50 ~ 70 ℃ .mol-1.min-1, the activation energy is 69.12 kJ · mol-1; when the stannous octoate is the catalyst, the reaction rate constant is in the range of 9.24 × 10-4 ~ 4.91 × 10-3 kg.mol-1.min -1, the activation energy of 76.98 kJ.mol-1. Experiments show that the catalytic activity of dibutyltin dilaurate is far greater than stannous octoate, is the preferred catalyst for this type of polymerization.