Diffusion in ethylene polymers. I. Desorption kinetics for a thin slab
Diffusion in ethylene polymers. I. Desorption kinetics for a thin slab
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在乙烯聚合物中的扩散。
DOI：
10.1002/pol.1957.1202611303
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发表时间：
1957
期刊：
影响因子：
--
通讯作者：
D. W. Mccall
中科院分区：
文献类型：
--
作者：
D. W. Mccall
本文介绍了从解吸数据确定固体中液体扩散系数的理论和实验。在实验上，解吸之后是称重固体样品。本文研究了从解吸数据中提取扩散系数的数学过程，并描述了一种可用于扩散系数与浓度相关的体系的数值过程。给出了苯和正己烷在两种乙烯聚合物中扩散的数据和分析。这两种聚合物是高支化高压材料和低压高结晶材料的代表。并对结果的分子意义进行了讨论。数值分析得到的解吸曲线也适用于扩散系数与浓度关系相似的其他体系。
Theory and experiments are described for the determination of diffusion coefficients liquids in solids from desorption data. Experimentally the desorption is followed by weighing the solid specimens. The mathematical process of extracting diffusion coefficients from desorption data is examined and a numerical procedure is described which may be employed in systems in which the diffusion coefficient is concentration-dependent. Data and analysis are presented for the diffusion of benzene and n-hexane in two ethylene polymers. The two polymers are representative of highly branched high pressure material and low pressure highly crystalline material. A discussion of the molecular significance of the results is given. The desorption curves obtained by numerical analysis are applicable to other systems which exhibit a similar dependence of the diffusion coefficient upon concentration.