N,N-二甲基甘氨酸酯表面活性剂的合成与表征

摘要

研究了以N,N-二甲基甘氨酸为起始原料,在较为温和的条件下,以甲烷磺酸为催化剂,甲苯为带水剂,合成N,N-二甲基甘氨酸酯的工艺,并对其亲水亲油平衡值(HLB)进行了测定.通过单因素试验考察了N,N-二甲基甘氨酸与醇的摩尔比、甲烷磺酸与N,N-二甲基甘氨酸摩尔比以及反应时间对产率的影响,合成产物的结构使用红外(FT-IR)和核磁共振(1H NMR)进行了表征.采用水数法测定了N,N-二甲基甘氨酸己醇、癸醇、正十六醇酯的HLB值.通过单因素试验得到的最佳合成条件为:N,N-二甲基甘氨酸与醇的摩尔比1.2∶1,甲烷磺酸与N,N-二甲基甘氨酸摩尔比2∶1,反应时间3 h.经测定,N,N-二甲基甘氨酸己醇、癸醇、正十六醇酯的HLB值分别为14.30,13.85,12.74.%The process of synthesis of N,N-dimethyl glycine ester is studied under mild conditions with N,N-dimethyl glycine as starting material, methane sulfonic acid as catalyst and toluene as dehydrant, and the hydrophilic lipophilic balance value (HLB) is measured.The effects of molar ratio of dimethyl glycine to alcohol, molar ratio of methane sulfonic acid to N,N-dimethyl glycine, and the reaction time on the yield are studied by single factor experiments, and the structure of the products are characterized by FT-IR and 1H NMR.The HLB values of N, N-dimethyl glycine hexanol, decyl alcohol and cetyl alcohol ester are measured by means of water number.The optimum technological conditions are obtained as follows: molar ratio of dimethyl glycine to alcohol is 1.2∶1, molar ratio of methane sulfonic acid to N, N-dimethyl glycine is 2∶1, the reaction time is 3 h.The HLB values of N,N-dimethyl glycine hexanol, decyl alcohol and cetyl alcohol ester are 14.30, 13.85 and 12.74, respectively.