Non-ionic surface active agents — Polyethoxylated derivatives — Determination of hydroxyl value — Acetic anhydride method
NORM herausgegeben am 1.3.1980
Bezeichnung normen: ISO 4326:1980
Ausgabedatum normen: 1.3.1980
Zahl der Seiten: 3
Gewicht ca.: 9 g (0.02 Pfund)
Land: Internationale technische Norm
Kategorie: Technische Normen ISO
Description / Abstract: 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.