聚乙二醇单甲醚羧基衍生物的制备

The preparation of carboxyl-monomethoxypoly(ethylene glycol)

摘要:

摘 要：以分子量为1200，2000，5000的聚乙二醇单甲醚（mPEG）为原料，采用琼斯试剂氧化法室温下制备羧基化的聚乙二醇单甲醚。经1HNMR和IR表征，产物为具有羧基的聚乙二醇单甲醚(CmPEG)。以羧基转化率为指标，探讨了反应物料最佳的物质的量比为：n(Cr2O3): n(聚乙二醇单甲醚羟基) =2：1，三种分子量产物的羧基转化率分别为99.6%，99.4%，98.0%。采用固液萃取法进行后处理，以产物外观颜色为指标，实验结果表明固液萃取法中，先蒸除丙酮再加入碳酸氢钠中和的处理顺序获得的产物的颜色为白色，产物纯度高。以产物产率为指标，以分子量为1000，1200，2000，5000的聚乙二醇单甲醚（mPEG），分子量为800的聚乙二醇（PEG）为原料，实验结果表明此方法适合于分子量大于2000的聚乙二醇，分子量大于1000的聚乙二醇单甲醚的羧基衍生物的制备，五种分子量产物的产率分别为88.2%，93.5%，98.0%，98.2%，39.1%。 关键词：聚乙二醇单甲醚；羧基化聚乙二醇单甲醚；琼斯试剂；Cr2O3

Abstract:

Abstract: This experiment used mPEG with the molecular weights of 1200, 2000 and 5000 as raw materials and adopted the Jones reagent oxidation method to produce CmPEG at ambient temperature. Characterized by 1HNMR and IR, the product was proved to be CmPEG. The carboxyl conversion rate was taken as the index to find out that the most proper molar ratio of Cr2O3 and mPEG was 2 to 1. The carboxyl conversion rates of three products with different molecular weights were 99.63%, 99.4% and 98% respectively. This experiment adopted the solid-liquid extraction technique to reprocess these products and taked the appearance and color as indices. The result shows that the product is produced to be white and of high purity in the order of distilling acetone first and adding sodium bicarbonate to neutralize them next. Taking the yield of these products as the index, used mPEG with the molecular weights of 1000,1200, 2000 ,5000 and PEG with the molecular weights of 800 as raw materials, the experiment shows that this method applies to the preparation of the carboxylic acid derivatives of PEG which molecular weight is more than 2000 and mPEG which molecular weight is more than 1000. The yield of these five products with different molecular weights are 88.2%,93.5%,98.0%,98.2%,39.1% respectively. key word: Methoxypolyethylene glycols; Carboxyl-mPEG; Jones reagent; Cr2O3