棕榈酰基蛋氨酸表面活性剂的合成与性能

以天然产物棕榈酸和蛋氨酸为原料,通过酰氯化反应和酰胺化反应两步法合成棕榈酰基蛋氨酸表面活性剂（PMS）,探究反应温度、反应时间、反应物摩尔比、反应介质体积比等因素对酰胺化反应的影响;通过傅里叶红外光谱（FTIR）、核磁共振氢谱（¹H NMR）和质谱对产物的结构进行表征;研究产物的表面性能和复配体系的性能。实验结果表明：酰胺化反应最佳反应温度为30℃、n(棕榈酰氯)∶n(蛋氨酸)=1∶1.2、V(水)∶V(丙酮)=1∶2、反应时间为2.5h,在此条件下,得到产物产率89.0%;表征的结果为目标产物;合成产物临界胶束浓度为 1.2×10^-4mol/L,表面张力为29.59mN/m;对苯等有机溶剂的乳化作用明显优于月桂酰基谷氨酸（LAS）;PMS与椰油丙基甜菜碱（CPBS）摩尔比为4∶6时复配体系表面活性最佳,临界胶束浓度达到9.5×10^-5mol/L,复配体系表面张力为28.1mN/m。

Synthesis and properties of palmitoyl methionine surfactant

Palmitoyl methionine surfactant (PMS) was synthesized using natural palmitic acid and methionine by acyl chloride reaction and amidation reaction. The effect of reaction temperature, molar ratio of reactants, reaction medium volume ratio, and reaction time on the amidation reaction was investigated by single factor experiment method. In addition, the structure of the product was characterized by FTIR、¹H NMR and mass spectra, and the surface properties of the product and the properties of the complex system were determined. The results showed that the optimal conditions of amidation reaction were screened out as follows: reaction temperature of 30℃, the molar ratio of reactants 1∶1.2, the volume ratio of reaction medium 1∶2, and the optimum reaction time 2.5h. Under the above conditions, the product yield was 89.0%. And the result of the characterization is the target product. Furthermore, the critical micelle concentration (CMC) and surface tension of product were 1.2×10^-4mol/L and 29.59mN/m, respectively. The emulsification of the product with many organic solvents was clearly superior to lauroyl glutamic acid surfactant(LAS). When the molar ratio of PMS and coconut oil propyl betaine surfactant (CPBS) was 4∶6, the surface properties of the complex system was the best. Under those conditions, the CMC and surface tension of the complex system were 9.5×10^-5mol/L and 28.1mN/m, respectively.