黏度法测定聚乙二醇分子量实验方法改进

摘要

Aiming at the multi-point extrapolation is time consuming, the traditional multi-point method of Ubbelohde viscometer determination of viscosity of polyethylene glycol (PEG) molecular weight experiment method was improved. Based on the "one point method of approximate formula, temperature at the temperature of T 250C , the relative error is to be in the range of ± 5%, to use the characteristic viscosity of PEG solution diluted the value of the conventional 6 h , experiment is shortened to 2h with satisfactory results.%针对"多点法"两曲线外推繁琐耗时,对传统的乌氏黏度计测定聚乙二醇(PEG)黏均分子量实验方法进行了方法和加料顺序的改进.基于"一点法"近似公式,在温度25℃下恒温,改变稀释溶液顺序,使常规6 h的物理化学学生实验缩短为2 h,其所得的特性黏度值相对误差在 ±5%范围内,测得PEG黏均分子量为5.9500×104与标签吻合.改进后的实验步骤方便快捷,结果满意.