封端法测定羟基硅油的羟基含量

摘要

以吡啶为缚酸剂,采用羟基硅油与过量二甲基氯甲基氯硅烷反应,产物提纯后直接由核磁共振氢谱算得羟基硅油的平均摩尔质量与羟基含量.该方法准确性和重现性较好,避免了传统LiAlH4测定方法中水分的干扰,适用于测定有确定分子式或有固定基团比例的羟基硅油.%The end-blocking product was prepared by HCL agent of pyridine,the hydroxyl silicone oil re-acted with the excess (chloromethyl)dimethylchlorosilane. Then it was purified and the average molecular weight and hydroxyl content in the silicone oil were determined by the calculation of the integration in 1H NMR spectrum. It featured with the high accuracy and good reproducibility, avoiding the traditional method with LiAlH4, since it could eliminate the interference of the water. It could be used to determine the hydroxyl con-tent in silicone oil with a definite molecular formulator or with the fixed proportion of hydroxyl silicone oil.