催化剂对IPDI的异氰酸酯基选择性的影响

Effect of the Catalyst on the Selectivity of -NCO in IPDI

分别以三乙胺(TEA)、1,4-二氮杂二环[2.2.2]辛烷(DABCO)、二月桂酸二丁基锡(DBTDL)、辛酸亚锡(SO)作催化剂,在甲苯溶液中进行了异佛尔酮二异氰酸酯(IPDI)与苯甲醇的反应,对比了IPDI中不同异氰酸酯基的反应活性,并探讨了催化剂、温度等对其活性差异的影响。结果表明,TEA、DABCO作催化剂时,IPDI中异氰酸酯基的活性差异并不明显;DBTDL、SO作催化剂时,则存在明显的活性差异,仲脂环异氰酸酯基的活性大于伯异氰酸酯基的活性,而且SO作催化剂时活性差异更加显著。此外,根据不同温度的反应速率常数计算了各异氰酸酯基的活化能:DBTDL作催化剂时,伯仲异氰酸酯基的活化能分别为62.68 kJ/mol和53.02 kJ/mol;SO作催化剂时,伯仲异氰酸酯基的活化能分别为63.60kJ/mol和57.01 kJ/mol。

The reaction between IPDI and benzyl alcohol in the solvent of toluene was catalyzed by trimethylamine （TEA）, 1,4-diazabicyclo [ 2.2.23 octane （I）ABCO）, dibutyltiondilaurate （DBTDL） and stannousoctanoate （SO）, respectively. A comparative research between the two - NCO groups in IPDI was done. The effects of temperature and catalyst were discussed. It shows that the difference of reactivity between the two -NCO groups is affected slightly by TEA or DABCO, while it is affected largely by DBTDL or SO. Cycloaliphatic -NCO reacted more rapidly than aliphatic -NCO, especially using SO as catalyst. The activation energy of aliphatic -NCO and Cycloaliphatic -NCO in DBTDL system is 62.68 kJ/mol and 53.02 kJ/mol respectively, and in the SO system is 63.60 kJ/mol and 57.01 kJ/mol respectively.