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.
| CSA Group | |
|---|---|
| Product Category | Standards and Technical Documents |
| Product Number | ISO 4326:1980 |
| Product Name | Non-ionic surface active agents - Polyethoxylated derivatives - Determination of hydroxyl value - Acetic anhydride method |
