GB/T 7383-2007 in English

《GB/T 7383-2007非离子表面活性剂 羟值的测定》由TC63（全国化学标准化技术委员会）归口，TC63SC8（全国化学标准化技术委员会(特种)界面活性剂分会）执行，主管部门为中国石油和化学工业联合会。
本标准规定了非离子表面活性剂羟值的测定。
本标准适用于脂肪族和脂环族的聚烷氧基化合物的羟值(特别是伯脂肪醇、烷基酚和脂肪酸的环氧乙烷、环氧丙烷及其混合物的加成物的羟值)的测定,适用于羟值在10~1000的测定。

Scope

This standard specifies the determination of the hydroxyl value of nonionic surfactants. This standard is applicable to the hydroxyl value of aliphatic and cycloaliphatic polyalkoxy compounds (especially the hydroxyl value of adducts of ethylene oxide, propylene oxide and their mixtures of primary fatty alcohols, alkylphenols and fatty acids) ) is suitable for the determination of hydroxyl value in the range of 10 to 1 000. The phthalic anhydride method is especially suitable for the determination of the hydroxyl value of ethylene oxide, propylene oxide and their mixed adducts of primary and secondary fatty alcohols, alkylphenols and fatty acids. The acetic anhydride method is especially suitable for the determination of the hydroxyl value of ethylene oxide adducts of primary and secondary fatty alcohols, alkylphenols and fatty acids, but not for the determination of the hydroxyl value of propoxylated products. Substances that may interfere are as follows: ——Primary and secondary amines, amides, tertiary alcohols, thiols and epoxides produce side reactions that affect the accuracy of the method. - Long chain aliphatic acids and esters form more stable anhydrides than phthalic anhydride and acetic anhydride, which cannot be completely decomposed at the end of the measurement. ——Other free acids cause interference due to the reaction with sodium hydroxide standard solution; alkalis, including some tertiary amines, cause interference due to the reaction with the generated phthalic acid and acetic acid. Degree for correction (according to GB/T 6365). The presence of epoxides interferes with the determination. If it can be removed by low-temperature vacuum distillation without changing the hydroxyl value, this method is still applicable. The above-mentioned treatment can eliminate free ethylene oxide that interferes with a concentration (mass fraction) higher than 0.5%. Moisture present in the sample will react with phthalic anhydride and acetic anhydride, but this method can still be used if the precautions described in the determination procedure are followed.