GB/T 7383-2020
Non-ionic surface active agents—Determination of hydroxyl value (English Version)

Standard No.

GB/T 7383-2020

Language

Chinese, Available in English version

Release Date

2020

Published By

国家市场监督管理总局、中国国家标准化管理委员会

Latest

GB/T 7383-2020

Replace

GB/T 7383-2007

Scope

This standard specifies the determination of hydroxyl value in nonionic surfactants. This standard is applicable to the hydroxyl value of aliphatic and cycloaliphatic polyalkoxy compounds (the hydroxyl value of adducts of ethylene oxide, propylene oxide and their mixtures of primary fatty alcohols, alkylphenols and fatty acids) Determination, suitable for the determination of hydroxyl value in 10~1000. The phthalic anhydride method is suitable for the determination of the hydroxyl value of the adducts of ethylene oxide, propylene oxide and their mixtures of primary and secondary fatty alcohols, alkylphenols and fatty acids. The acetic anhydride method is 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. The near-infrared method is suitable for nonionic surfactants whose hydroxyl value can be determined by the phthalic anhydride method or the acetic anhydride method. Interfering substances are as follows: ——Primary and secondary amines, amides, tertiary alcohols, mercaptans and epoxides produce side reactions that affect the accuracy of the method. --- Long carbon chain aliphatic acids and esters will produce more stable anhydrides than phthalic anhydride and acetic anhydride, which cannot be completely decomposed at the end of the measurement. ——Other free acids interfere with the reaction with the sodium hydroxide standard solution, and alkalis, including certain tertiary amines, interfere with the generated phthalic acid and acetic acid. The presence of epoxides interferes with the determination. If they 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%. The moisture present in the sample will react with phthalic anhydride and acetic anhydride, but this method is still applicable if the measures described in the determination procedure are followed to prevent it.

GB/T 7383-2020 Referenced Document

• GB/T 11275 Surface active agents.Determination of water content
• GB/T 2384 Dyes intermediates—General method for the determination of melting range*， 2021-12-31 Update
• GB/T 29858 Standard guidelines for molecular spectroscopy multivariate calibration quantitative analysis
• GB/T 3143 Color determination method of liquid chemicals(Hazen unit--Platinum-cobalt scale)
• GB/T 601 Chemical reagent.Preparations of reference titration solutions
• GB/T 6365 Surface active agents. Determination of free alkalinity or free acidity. Titrimetric method
• GB/T 6372 Surface active agents and detergents. Methods of sample division
• GB/T 7383-2020 Non-ionic surface active agents—Determination of hydroxyl value
• GB/T 8170 Rules of rounding off for numerical values & expression and judgement of limiting values
• ISO 4327 Non-ionic surface active agents; Polyalkoxylated derivatives; Determination of hydroxyl value; Phthalic anhydride method

GB/T 7383-2020 history

• 2020 GB/T 7383-2020 Non-ionic surface active agents—Determination of hydroxyl value
• 2007 GB/T 7383-2007 Non-ionic surface active agents.Determination of hydroxyl valu
• 1997 GB/T 7383-1997 Non-ionic surface active agents--Polyalkoxylated derivatives--Determination of hydroxyl value--Phthalic anhydride method
• 1996 GB/T 7384-1996 Non-ionic surface active agents--Polyethoxylated derivatives--Determination of hydroxyl value--Acetic anhydride method