黏度法测定高聚物摩尔质量的对比分析

Comparison and Discussion on Molar Mass Determination of Polymers by Viscosity Method

黏度法测定高聚物的摩尔质量是高等院校物理化学实验课必开的实验教学内容之一,实验教学中常采用乌氏黏度计进行测定。利用乌氏及奥氏黏度计在30℃时对聚乙烯醇和聚乙二醇高聚物的摩尔质量进行测定对比,发现奥氏黏度计对聚乙烯醇的测定具有更高的实验准确度,并且奥氏黏度计具有结构简单、不易损坏和测试过程不易受气泡干扰等优点。因此,在测定高聚物摩尔质量时需要根据高聚物的性质选择不同类型的黏度计,该结果为高等院校的物理化学实验教学提供重要参考依据。

Determination of molar mass of polymers by viscosity method is one of the necessary teaching contents of physical chemistry experiment course in colleges and universities.Ubbelohde viscometer is often used in experimental teaching.The molar mass of polyvinyl alcohol and polyethylene glycol solution was measured and compared by Ubbelohde and Ostwald viscometer at 30℃in this paper.It was found that the determination of polyvinyl alcohol polymer by Ostwald viscometer had higher experimental accuracy,and Ostwald viscometer had the advantages of simple structure,not easy to be damaged and disturbed by bubbles in the test process.Therefore,it is necessary to select different types of viscometers according to the properties of polymers when measuring the molar mass of polymers.The results provide important reference for physical chemistry experiment teaching in colleges and universities.