二甲胺歧化对脂肪醇催化胺化反应的影响

Effects of disproportionation of dimethylamine onthe catalytic amination of fatty alcohols

双长链烷基甲基叔胺是脂肪醇和二甲胺催化胺化反应的主要副产物。对月桂醇和二甲胺催化胺化反应体系中主要副产物双十二烷基甲基叔胺的生成量和循环气相所含三甲胺的量进行跟踪分析 ,发现前者的量和后者的量之间成正变关系 ,直接证明了二甲胺的歧化和双十二烷基甲基叔胺生成之间的联系。脂肪醇胺化反应物选择性主要取决于二甲胺的歧化程度。二甲胺的歧化除引起副产物的生成之外 。

Dialkylmethylamines are the main by-products in t he catalytic of fatty alcohols.The amounts of didodecylmethylamine(DDMA) as main by-product and trimethylamine(TMA)in the reaction system of catalytic amination of dodecyl alcohol with dimethylamine(DMA)were analyzed.We found that the conte nt of DDMA in the liquid phase was increased along with the content of TMA in th e circulated gas phase,and there was definite relation between the formation of DDMA and disproportionation of DMA.The disproportionation of DMA causes the lowe r selectivity of the reaction,effects the control of the operating conditions du ring the reaction,and may have a little environmental problem.