椰子油酰基芳香族氨基酸盐的绿色合成与性能评价

Green synthesis and properties characterization of coconut oil acyl aromatic amino acid surfactants

摘要:

采用绿色合成方法，利用椰子油与含芳香环取代基的组氨酸钠、苯丙氨酸钠、酪氨酸钠直接进行酰胺化反应制备了三种椰子油酰基芳香族氨基酸盐。采用高效液相色谱-质谱联机、红外光谱对产物组成和结构进行了表征，并对合成产品的性能进行了测定。结果表明，椰子油酰基氨基酸盐表面活性剂的界面性能受氨基酸结构的影响较大，椰子油酰基苯丙氨酸钠与椰子油酰基组氨酸钠的临界胶束浓度（CMC）分别为9.84×10-5 和6.79×10-5 mol/L，均远远小于椰子油酰基酪氨酸钠的CMC（1.54×10-2 mol/L）。三种椰子油酰基氨基酸盐表面活性剂均具有良好的乳化性、起泡性及泡沫稳定性，乳液分出10 mL水相最长需要342 s，泡沫高度最高达到157 mm，H5/H1最高达到0.898；耐硬水性等同或优于皂类；在蒸馏水中的去污力均优于直链烷基苯磺酸钠（LAS）、α-烯基磺酸钠（AOS）、椰子油钠皂等传统表面活性剂。

Abstract:

Three kinds of coconut oil acyl aromatic amino acid salts were prepared by amination of coconut oil with histidine sodium, phenylalanine sodium, and tyrosine sodium, which containing aromatic cyclic substituents, by a green synthesis method. The composition and chemical structures were confirmed by high-performance liquid chromatography- mass spectrum (HPLC/MS) and infrared (IR) spectra. The properties of the synthetic products were determined. The interfacial properties depend significantly on amino acid types. The critical micelle concentrations (CMC) of coconut acyl phenylalanine sodium and coconut acyl histidine sodium were 9.84×10-5 mol/L and 6.79×10-5 mol/L, respectively, which were far smaller than that of coconut acyl tyrosine sodium (1.54×10-2 mol/L). The sodium coconut acyl amino acid surfactants exhibited good emulsification and foaming stability. The maximum separation time of 10 mL aqueous phase from emulsion was 342 seconds. The foam height reached 157 mm, and the H5/H1 reached 0.898. Hard water resistance of the three amino acid surfactants was equal or better than that of soap. The detergency ability in distilled water of acyl amino acid surfactants was better than multiple traditional surfactants, like sodium linear alkylbenzene sulfonate (LAS) and sodium alpha-olefin sulfonate (AOS), and sodium soap of coconut oil.