C22醇烷基磷酸酯乳化剂的制备与结构表征

Synthesis and Characterization of Behenyl alcohol Alkyl Phosphate Emulsifier

摘要:

以C22醇和P2O5为原料合成一种C22醇烷基磷酸酯乳化剂，设计正交实验考察了C22醇与P2O5的投料摩尔比、酯化温度、酯化时间对产物中双烷基磷酸酯（DAP）、单烷基磷酸酯(MAP)和残余磷酸(PA)组成的影响，对实验条件进行优化，确立最佳合成条件为：C22醇与P2O5的投料摩尔比为5:1，酯化温度85 ℃，酯化时间为6 h。正交实验结果表明在最佳条件得到的产物中DAP的含量高于MAP的含量，PA的含量为0.66%。测试不同PH值下乳液的乳化稳定性指数(ESI)和乳化活性指数(EAI)，结果表明在pH=6~7之间乳化效果最佳；以辛癸酸甘油酯(GTCC)和橄榄油为油脂验证产物的乳化能力，结果表明所得产物的乳化能力强，并且所得的乳化体系稳定。利用红外光谱和31P-NMR对产物结构进行了表征，红外光谱结果表明P2O5与C22醇发生了酯化反应，生成了C22醇烷基磷酸酯；31P–NMR结果表明C22醇烷基磷酸酯产物中包含DAP和MAP。

Abstract:

Alkyl phosphate，an emulsifying agent, was synthesized with behenyl alcohol and phosphoric anhydride as the starting materials. Effects of the molar ratio of behenyl alcohol and phosphoric anhydride, esterification temperature and esterification time on the product composition were investigated by orthogonal experiments. The optimum molar ratio of behenyl alcohol and phosphoric anhydride, esterification temperature and esterification time were 5:1, 85 ℃, 6 h, respectively. Under the optimum conditions, the mass fraction of di-alkyl phosphate (DAP) was higher than mono-alkyl phosphate (MAP), and the residual phosphoric acid (PA) in the product was 0.66%. The results of ESI and EAI of emulsion showed that when pH was 6~7, the emulsifying effect of product was best. The strong capacity and emulsifying stability of product were confirmed by emulsifying test in which oil phase was GTCC and olive oil. The product structure was confirmed through IR and31P-NMR and the results showed that DAP and MAP were included in the product.