当前位置: X-MOL 学术J. Chem. Eng. Data › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Densities, Viscosities, and Self-Diffusion Coefficients of Ethylene Glycol Oligomers
Journal of Chemical & Engineering Data ( IF 2.0 ) Pub Date : 2021-05-05 , DOI: 10.1021/acs.jced.1c00101
Markus M. Hoffmann 1 , Rachel H. Horowitz 1 , Torsten Gutmann 2 , Gerd Buntkowsky 2
Affiliation  

Polyethylene glycol (PEG) is gaining interest as an alternative green solvent in chemical synthesis and processing. This report presents density and viscosity data from 293.15 K to 358.15 K as well as self-diffusion coefficient data from 298.15 K to 358.15 K for oligomers of PEG from di- to nonaethylene glycol. The results were obtained by extrapolation from measurement series where water, the most common impurity in PEGs, was intentionally added in several increments. The obtained results are carefully compared to literature data, which are widely available only for density and viscosity, and only for the lower oligomers. Densities are found to be linearly dependent on temperatures for all studied oligomers. The temperature dependence of viscosity and self-diffusion coefficients show only slight deviations from the Arrhenius equation over the investigated temperature range. The activation energies obtained from the viscosity data agree well with the activation energies from the self-diffusion coefficient data and appear to be linearly dependent with respect to the number of ethylene oxide repeat units in the PEG oligomer. This linearity combined with the observation that the pre-exponential factor appears to be the same for all studied oligomers may serve as a tool to estimate viscosities and self-diffusion coefficients for higher oligomers within the investigated temperature range. The densities of the oligomers all fall within a rather narrow range without a clear trend in homologous series.

中文翻译:

乙二醇低聚物的密度、粘度和自扩散系数

聚乙二醇 (PEG) 作为化学合成和加工中的替代绿色溶剂越来越受到关注。本报告提供了 293.15 K 至 358.15 K 的密度和粘度数据以及 298.15 K 至 358.15 K 的 PEG 低聚物的自扩散系数数据,从二乙二醇到九乙二醇。结果是通过从测量系列外推获得的,其中水是 PEG 中最常见的杂质,有意以几个增量添加。所得结果与文献数据进行了仔细比较,文献数据仅适用于密度和粘度,并且仅适用于较低的低聚物。发现所有研究的低聚物的密度都与温度呈线性关系。在所研究的温度范围内,粘度和自扩散系数的温度依赖性仅显示出与阿伦尼乌斯方程的轻微偏差。从粘度数据获得的活化能与来自自扩散系数数据的活化能非常吻合,并且似乎与 PEG 低聚物中环氧乙烷重复单元的数量呈线性相关。这种线性与所有研究的低聚物的指数前因子似乎相同的观察结果相结合,可以作为在研究的温度范围内估计更高低聚物的粘度和自扩散系数的工具。低聚物的密度都在较窄的范围内,没有明显的同源系列趋势。从粘度数据获得的活化能与来自自扩散系数数据的活化能非常吻合,并且似乎与 PEG 低聚物中环氧乙烷重复单元的数量呈线性相关。这种线性与所有研究的低聚物的指数前因子似乎相同的观察结果相结合,可以作为在研究的温度范围内估计更高低聚物的粘度和自扩散系数的工具。低聚物的密度都在较窄的范围内,没有明显的同源系列趋势。从粘度数据获得的活化能与来自自扩散系数数据的活化能非常吻合,并且似乎与 PEG 低聚物中环氧乙烷重复单元的数量呈线性相关。这种线性与所有研究的低聚物的指数前因子似乎相同的观察结果相结合,可以作为在研究的温度范围内估计更高低聚物的粘度和自扩散系数的工具。低聚物的密度都在较窄的范围内,没有明显的同源系列趋势。这种线性与所有研究的低聚物的指数前因子似乎相同的观察结果相结合,可以作为在研究的温度范围内估计更高低聚物的粘度和自扩散系数的工具。低聚物的密度都在较窄的范围内,没有明显的同源系列趋势。这种线性与所有研究的低聚物的指数前因子似乎相同的观察结果相结合,可以作为在研究的温度范围内估计更高低聚物的粘度和自扩散系数的工具。低聚物的密度都在较窄的范围内,没有明显的同源系列趋势。
更新日期:2021-06-10
down
wechat
bug