乙二醇葡糖苷的合成及保湿性研究

在磷酸催化下 ,由葡萄糖和乙二醇经缩醛化反应制备了乙二醇葡糖苷 ,可用作化妆品保湿剂。采用高效液相色谱跟踪监控反应进程 ,并确定了乙二醇葡糖苷的组成。反应在 130℃、5 3kPa下进行 ,减压蒸除反应生成的水。醇糖的量比是 3∶1或 5∶1,催化剂占葡萄糖质量的 2 % ,过量乙二醇在 4 0 0～ 0 6 7kPa下减压蒸除 ,残糖质量分数小于 1%。合成的乙二醇葡糖苷具有优良的保湿性能 ,当m (羟乙基葡糖苷 )∶m (乙二醇二葡糖苷 ) =0 73∶1 0 0时 ,质量分数为 70 %的乙二醇葡糖苷水溶液的保湿能力比质量分数为 70 %的甘油水溶液高 11 1%。羟乙基葡糖苷的含量越高 ,产品的保湿性越好。

Preparation of Ethylene Glycol Glycosides for Humectant in Cosmetics

Ethylene glycol glycosides,useful as humectant in cosmetics,were prepared by phosphoric acid-catalyzed acetalization of glucose with ethylene glycol.High performance liquid chromatography (HPLC) was developed for monitoring the kinetics of the title synthesis and identifying the components of mixtures of ethylene glycol glycosides.The reaction was carried out at 130 ℃and 5 3 kPa,the water formed being removed by distillation.Glycol and glucose were employed in molar ratio of 3∶1 or 5∶1 and the catalyst used was 2% by weight of the amount of glucose.Excess glycol was removed by distillation at 4 0 - 0 67 kPa.The content of residual glucose fell to below 1% by weight,of the amount of glycol glycosides.Mixtures of glycol glycosides with excellent moisture retentiveness were obtained.When mass ratio of hydroxyethylglucoside to glycol diglucoside was 0 73∶1 00,the ability of moisture control of 70% aqueous glycol glycosides solution was 11 1% higher than that of 70% aqueous glycerol solution.The higher the content of hydroxyethylglucoside, the better the moisture retentiveness of the product.