标准摘要
[中文适用范围]： 羟基在吡啶溶液中被乙酸酐酯化。 过量的乙酸酐用水水解。 在酚酞作为指示剂存在下，用氢氧化钠溶液中和酯化过程中出现的酸性和水解过程中形成的乙酸。 根据滴定空白溶液和测试溶液所用氢氧化钠溶液的体积之差计算羟值。 [外文原描述]： The hydroxyl group is esterified by acetic anhydride in pyridine solution. The excess of acetic anhydride is hydrolized with water. The acidity which appears during the esterification and the acetic acid formed during the hydrolysis are neutralized by sodium hydroxide solution in the presence of phenolphthalein as indicator. The hydroxyl value is calculated from the difference between the volume od sodium hydroxide solution used for the titration of the blank and of the test solution.
英文名称Non-ionic surface active agents — Polyethoxylated derivatives — Determination of hydroxyl value — Acetic anhydride method