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	用Simha-Somcynsky状态方程改进高分子中溶剂扩散系数模型
	吕宏凌 ; 王保国 ; 杨基础 ; Lv Hongling ; WANG Baoguo ; YANG Jichu
	2010-06-10 ; 2010-06-10
关键词	高分子 溶剂 扩散系数 状态方程 polymer solvent diffusion coefficient equation-of-state(EOS) TQ021.4
其他题名	A modified model of diffusion coefficient in polymer-solvent systems based on Simha-Somcynsky equation-of-state
中文摘要	将SimhaSomcynsky状态方程和VrentasDuda的自由体积理论模型相结合,提出改进的高分子中溶剂扩散系数模型.改进的模型利用状态方程和WLF理论定义的自由体积分数确定扩散过程的有效自由体积,避免原模型中繁琐的黏弹性实验测定.对苯、甲苯、乙苯、氯仿在聚苯乙烯、聚异丁烯和聚醋酸乙烯酯中的扩散系数的计算结果表明,改进模型的预测值与实验值取得较好一致,且自扩散系数的预测精度比原模型高.同时,改进的模型能够反映压力对扩散系数的影响.溶剂扩散系数随外界压强增加而减小,当溶剂浓度较低时,压强的影响非常显著,扩散系数可相差几个数量级.随着溶剂浓度升高,扩散系数接近常压时的扩散系数,压强影响可以忽略.; A modified diffusion model for polymer-solvent systems was proposed by introducing the Simha-Somcynsky(SS)equation-of-state(EOS)into the Vrentas-Duda free-volume model.The complex process of viscoelastic measurements in the Vrentas-Duda model was avoided successfully,since the effective free volume of a polymer can be estimated from the SS EOS together with the Williams-Landel-Ferry(WLF)fractional free volume.Calculated diffusion coefficients of benzene,toluene,ethylbenzene and chloroform in polystyrene,polyisobutylene and poly(vinyl acetate)indicated that predictions from the modified model were consistent with experimental values,and the accuracy was better than those from the Vrentas-Duda model for predicting solvent self-diffusion coefficients.Moreover,the modified model can reflect the effect of pressure on diffusion coefficients.Solvent diffusion coefficients in polymers decrease with increasing pressure.Especially in dilute polymer-solvent systems,diffusion coefficients change by several orders of magnitude with increasing pressure.With the increase of solvent concentration,diffusion coefficients gradually approach those values under atmospheric pressure,thus the effect of pressure can be neglected reasonably.; 国家自然科学基金项目(20276033,20276014); 国家重点基础研究发展计划项目(2003CB615701).~~
语种	中文 ; 中文
内容类型	期刊论文
源URL	[http://hdl.handle.net/123456789/64076]
专题	清华大学
推荐引用方式 GB/T 7714	吕宏凌,王保国,杨基础,等. 用Simha-Somcynsky状态方程改进高分子中溶剂扩散系数模型[J],2010, 2010.
APA	吕宏凌,王保国,杨基础,Lv Hongling,WANG Baoguo,&YANG Jichu.(2010).用Simha-Somcynsky状态方程改进高分子中溶剂扩散系数模型..
MLA	吕宏凌,et al."用Simha-Somcynsky状态方程改进高分子中溶剂扩散系数模型".(2010).

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