GB/T 7383-2020 Translated English of Chinese Standard (GB/T 7383-2020, GBT7383-2020): Non-ionic surface active agents -- Determination of hydroxyl value [Buy--download True-PDF in 3-second: https://play.google.com/books > Sign in > This BOOK > "3-dots" > Export > Save as "*.pdf"]https://www.chinesestandard.net, 25. juuni 2023 - 35 pages This Standard specifies the determination of hydroxyl value in non-ionic surface active agents. This Standard is applicable to the determination of hydroxyl value (the hydroxyl value of adducts of ethylene oxide and propylene oxide of primary fatty alcohols, alkylphenols and fatty acids, and their mixtures) of aliphatic and cycloaliphatic poly alkoxy compounds, which is suitable for the determination of hydroxyl value in 10 ~ 1,000. The phthalic anhydride method is suitable for the determination of the hydroxyl value of adducts of ethylene oxide and propylene oxide of primary and secondary fatty alcohols, alkylphenols and fatty acids, and their mixtures. The acetic anhydride method is suitable for the determination of the hydroxyl value of adducts of ethylene oxide 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 non-ionic surface active agents 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, thiols and epoxides generate side reactions that affect the accuracy of the method. ---Long-chain aliphatic acids and esters generate more stable anhydrides than phthalic anhydride acetic anhydride, which cannot be completely decomposed at the end of the determination. ---Other free acids cause interference due to the reaction with the sodium hydroxide standard solution, and alkalis, including certain tertiary amines, cause interference due to the reaction with the generated phthalic acid and acetic acid. The presence of epoxides interferes with the determination. If they can be removed by the low-temperature vacuum distillation method without changing the hydroxyl value, this method is still applicable. The above-mentioned treatment can eliminate free ethylene oxide that causes interfere... |
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abnormal value accordance with Formula Alcohol Polyoxyethylene Ethers anhydride pyridine solution Appendix arbitration method arithmetic mean blank tests burette The capacity calibration model capacity is 250 central hole condenser tube conical ground glass content mass fraction Determination of Hydroxyl determination results esterification estimated hydroxyl value ethylene oxide expressed in mL fatty alcohols Figure C.2 Flat-bottomed flask fume hood ground glass joints Ground glass stopper Hazen units hydroxide standard solution hydroxide standard titration Isomeric Tridecyl Alcohol Mahalanobis distance method specified mg/g mL of sodium modeling sample set Non-ionic Surface Active Null added phenolphthalein indicator phthalic acid phthalic anhydride method pipette potassium hydroxide pyridine solution acylation sample tube Sample-2 sodium hydroxide standard solution acylation reagent solution to titrate specified in GB/T standard hydroxyl value standard titration solution stipulations of GB/T Surface Active Agents Table E.1 temperature titration solution consumed Tridecyl Alcohol Polyoxyethylene Tube Validation validation sample set water content mass