N,N-二甲基甘氨酸酯表面活性剂的合成与表征

Synthesis and characterization of N,N-dimethyl glycine ester surfactants

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3h。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 A^,A^-dimethyl glycine ester is studied under mild conditions with A^-dimethyl glycine as starting material, methane sulfonic acid as catalyst and toluene as dehydrant, and the hydrophilic lipophilic balance value （H L B ） is measured. The effects of molar ratio of dimethyl glycine to alcohol, molar ratio of methane sulfonic acid to A^-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 1 H NMR . The HLB values of N - dimethyl glycine hexanol, decyl alcohol and cetyl alcohol ester are measured by means of wa-ter 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 - dimethyl glycine is 2 - 1 , the reaction time is 3 h. The H L B values of A^-dimethyl glycine hexanol, decyl alcohol and cetyl alcohol ester are 14. 30, 13. 85 and 12. 74, respectively.