Abstract

The dynamic viscosity and density of a water–PEG–KBr system are measured in the ranges of 293.15–323.15 K and 0–0.001 mol parts. Polyethylene glycol samples with average molecular weights of 1000, 1500, 3000, 4000, and 6000 g/mol are used. The concentration of KBr is 0.01 mol parts. The activation parameters of viscous flow (Gibbs energy, enthalpy, and entropy) and the partial molar volume of PEG in a solution are calculated using experimental data in the specified range of temperatures and concentrations. It is shown that the activation parameters of viscous flow grow along with concentration and molar weight. It is found that the partial molar volume of PEG in a solution falls as the concentration rises, and the partial molar volume per monomer does not change, depending on the average molecular weight of PEG. A simple way of determining the hydration number of a polymer molecule is described, based on which the hydration number of a PEG macromolecule in a solution is calculated. It is found that the hydration number of a PEG macromolecule falls as the temperature rises and grows along with the molecular weight.

中文翻译：

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水–PEG–KBr系统的粘度和密度研究

摘要

水–PEG–KBr系统的动态粘度和密度的测量范围为293.15–323.15 K和0–0.001 mol份。使用平均分子量为1000、1500、3000、4000和6000 g / mol的聚乙二醇样品。KBr的浓度为0.01摩尔份。使用在指定温度和浓度范围内的实验数据，计算粘性流动的激活参数（吉布斯能量，焓和熵）和溶液中PEG的部分摩尔体积。结果表明，粘性流的活化参数随浓度和摩尔质量的增加而增加。发现随着浓度的增加，溶液中PEG的部分摩尔体积下降，并且每个单体的部分摩尔体积不变化，这取决于PEG的平均分子量。描述了一种确定聚合物分子水合数的简单方法，基于该方法可以计算溶液中PEG高分子的水合数。发现随着温度的升高和分子量的增长，PEG大分子的水合数降低。