脂肪醇聚氧乙烯醚羟值的检测方法的改进

以4-二甲氨基吡啶为催化剂,过量乙酸酐为乙酰化试剂,吡啶为溶剂,用电位滴定法快速测定脂肪醇聚氧乙烯醚(AEO)的羟值,并对催化剂、反应条件、系统的适应性进行了探讨。用该方法对5种不同羟值的AEO样品进行了测定,测定结果的相对标准偏差0.5%(n=6),且测定结果与国标法测定结果的相对误差在±1%之内。

The testing method improvment of hydroxyl value of fatty alcohol ethoxylates (AEO)

The hydroxyl value of fatty alcohol ethoxylates (AEO) is determined rapidly in the method of potentiometric titration by making use of the 4-dimethylaminopyridine (DMAP) as catalyst, the excess of acetic anhydride as acetylation reagent, pyridine as the solvent. Meanwhile, the adaptability of the catalyst, the reaction conditions is discussed. By applying this method, five different hydroxyl value of fatty alcohol ethoxylates (AEO) samples were measured. The relative standard deviation of the measurement results were below 0.5% (n = 6) , according with the measurement in national standard method(within 1%).