催化剂对二元醇伯仲羟基氨酯化反应的影响

Effect of the Catalyst on the Urethane Reaction Selectivity of Different Hydroxyl in Diol

分别以甲苯、乙酸丁酯和N,N-二甲基甲酰胺作溶剂,以三乙胺(TEA)、1,4-二氮杂二环[2.2.2]辛烷(DABCO)作催化剂,进行1,2-丙二醇、1,3-丁二醇与苯基异氰酸酯的反应。用在线红外光谱监测反应过程,研究了二元醇中不同类型羟基的反应活性。结果表明,催化剂能够扩大伯羟基与仲羟基的反应活性差异。以甲苯作溶剂、TEA作催化剂时,1,2-丙二醇中伯羟基与仲羟基的活性差异最大,可达11倍左右。在相同条件下与苯基异氰酸酯反应时,1,2-丙二醇、1,3-丁二醇的反应速率相近,两者伯羟基与仲羟基的活性差异也相近。

The urethane reaction of 1,2-propylene glycol or 1,3-butylene glycol with phenyl isocyanate was investigated with toluene,butyl acetate or N,N-dimethylformamide as solvents and trimethylamine（TEA） or 1,4-Diazabicyclooctane（DABCO） as catalyst,respectively.A comparative research between the primary and secondary hydroxyl groups in diol was done.It showed that the reactivity difference between the two hydroxyl groups was affected by amine catalyst.The reactivity difference of hydroxyl groups in 1,2-propylene glycol was nearly 11 when TEA was used as catalyst and toluene was used as solvent.When reacting with phenyl isocyanate at the same condition,1,3-butylene glycol showed similar rate constants compared with 1,2-propylene glycol,the reactivity difference of primary and secondary hydroxyl group in 1,3-butylene glycol was also very similar to 1,2-propylene glycol.