通过动力学控制增强水热条件下α-氯代十二酸与三甲胺的氨解反应

Strengthen Amination of α-Chlorododecanoic Acid with Trimethylamine in Hydrothermol System by means of Kinetic Control

摘要:

α-氯代十二酸(α-chlorododecanoic acid，α-CDA)与三甲胺（TMA）在水热条件下经氨解反应可以合成新型两性表面活性剂α-癸基甜菜碱(α-capric betaine，α-CB)，但水解副反应的竞争使α-CB产率偏低。在优化了溶剂、投料比等因素的基础上，通过采用动力学控制手段——程序升温，有效地抑制了水解副反应从而显著提高了产物α-CB的产率。当n(TMA) / n(α-CDA) = 3时，以KI为催化剂且m(KI) / m(α-CDA) = 1%，预先添加质量分数为0.5%的α-CB，在70 ℃下反应8 h再升温至100 ℃继续反应2 h后，α-CB的产率从非程序升温时的62.4%提高到程序升温后的92%。

Abstract:

α-Capric betaine(α-CB), a new type of zwitterionic surfactant was synthesized by amination of α-chlorododecanoic acid(α-CDA) with trimethylamine(TMA) under hydrothermal condition, and the bothering was that the yield of α-CB was lower caused by the side effect of hydrolysis. Based on the optimal factors such as solvent, feed ratio, etc, the temperature program, a means of kinetic control, was applied to effectively inhibit hydrolysis and thus the yield of α-CB was markedly improved. When kept n(trimethylamine) / n(α-CDA) = 3, 1% of KI as catalyst and 0.5% of α-CB as solubilizer added in advance, the amination proceeded at 70 ℃ for 8 h followed 100 ℃ for 2 h, the yield of α-CB was improved from 62.4% to 92%.