Codes & Standards - Purchase
ISO 4326:1980
Non-ionic surface active agents -- Polyethoxylated derivatives -- Determination of hydroxyl value -- Acetic anhydride method
SKU: iso_010199_103757
Published by ISO
Publication Year 1980
1 Edition
3 pages
Product Details
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.