Gas Diffusion in Anisotropic Nonhomogeneous Polymers

✍ Scribed by Steven Grisafi

• Book ID: 102496213
• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 192 KB
• Volume: 18
• Category: Article
• ISSN: 1022-1344
• DOI: 10.1002/mats.200800061

✦ Synopsis

Abstract

In an effort to address the situation of gas diffusion in polymers that undergo swelling during the absorption process, two mass flux constitutive relations, independent of Fick's law, are evaluated. Both mass flux relations utilize the mass diffusivity as a tensor quantity. The diffusivity tensor considered can be a function of both time and spatial coordinates. For the case of one‐dimensional diffusion, approximations are found relating the diffusivity, when it is considered to be time varying and a function of position in the polymer, to the constant diffusivity assumed by Fick's law and its predicted concentration profile. Analyzing a case of oxygen absorption by glassy poly(ethylene terephthalate) shows a time‐dependent diffusivity with negligible spatial variation.

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