化学学报 ›› 2001, Vol. 59 ›› Issue (1): 34-38. 上一篇    下一篇

研究论文

环己烷在聚乙烯和聚异丁烯中无限稀释扩散系数 的测定

蒋文华;刘华;韩世钧   

  1. 浙江大学化学系.杭州(310027)
  • 发布日期:2001-01-15

Measurement of infinite dilution diffusion coefficients of cyclohexane in polyethylene and polyisobutylene

Jiang Wenhua;Liu Hua;Han Shijun   

  1. Zhejiang Univ, Dept Chem.Hangzhou(310027)
  • Published:2001-01-15

采用填充柱的反相气相色谱方法,基于Hadj-Romdhane-Danner色谱过程的数学模型,在323.2~363.2K温度范围内测定了环己烷在聚异丁烯和聚乙烯膜中的无限稀释扩散系数。从实验数据可以看出,环己烷更容易在PIB中发生扩散。对实测扩散数据进行了自由体积理论关联,结果表明,采用空穴自由体积替代Vrentas-Duda自由体积理论方程中自由体积项的修正方程能很好地描述溶剂分子扩散系数随温度的变化关系。

关键词: 环己烷, 聚乙烯, 聚异丁烯, 扩散系数, 自由体积, 聚合物膜

Based on the Hadj-Romdhane-Danner mathematical model of the chromatographic process, the infinite dilution diffusion coefficients of cyclohexane in polyethylene (PE) and polyisobutylene (PIB) were measured in the temperature range between 323.2 and 363.2K by reverse gas chromatography. The experimental data show that the diffusion data of cyclohexane in PE are smaller than those in PIB at the same temperature, which indicates that the diffusion of cyclohexane in PE membrane is more difficult if compared with PIB membrane. The correlation of the experimental data was performed by using the modified Vrentas-Duda free-volume equation, where the hole free volume was introduced instead of the whole free volume in the Vrentas- Duda initial equation. The correlated results show that the modified equation is a quite good description of the relationship between the observed diffusion data and the temperature.

Key words: CYCLOHEXANE, POLYETHYLENE, POLYISOBUTYLENE, DIFFUSION COEFFICIENTS, FREE VOLUME, POLYMER FILMS

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