N-酰化改性己二胺的固化反应动力学

采用酰基化方法对二胺扩链剂己二胺进行了改性以减缓聚脲的高反应活性带来的问题,并研究了合成反应的动力学方程.以己二胺、冰乙酸为原料,合成了新型位阻型扩链剂二乙酰己二胺,并用凯氏定氮法、红外光谱法和核磁共振氢谱分析确定了合成产物的化学结构.将它和端氨基聚醚、4,4′-二苯甲烷二异氰酸酯通过2步溶液法合成了新型聚脲,考察了二乙酰己二胺对聚脲凝胶时间的影响,并用傅里叶变换红外光谱仪原位跟踪该反应过程的固化反应动力学.结果表明该体系反应表现为良好的二级动力学关系.

N-acetylating Hexamethylene-diamine Curing Reaction Kinetics

Diacetyl hexamethylene-diamine, a new chain extender, was prepared with hexamethylene-diamine, acetic acid and phosphoric for decreasing reaction activity of synthesizing polyurea. Micro-kjeldahl method, FTIR and ~1H-NMR were employed to characterize chemical structure of the synthetic product. Polyureas were synthesized using 4,4′-diphenyl diisocyanate and amine terminated poly (oxypropylene) with two different chain extenders. The gel time is prolonged, that is, the reaction activity is decreased when diacetyl hexamethylene-diamine is used as chain extender instead of hexamethylene-diamine. The kinetics of curing of polyurea reaction was studied by FTIR. The results show that the reaction belongs to the second-order reaction.