Finite difference modeling of the gas transport process in glassy polymers

✍ Scribed by J. B. Brolly; D. I. Bower; I. M. Ward

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 632 KB
• Volume: 34
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(199603)34:4<761::aid-polb17>3.0.co;2-f

✦ Synopsis

Finite difference modeling has been used to predict the results of gas transport experiments for a concentration-dependent diffusion coefficient. Experiments on the transport of C 0 2 in poly(ethy1ene terephthalate) and poly(ethy1ene naphthalate) had previously shown a difference between the effective diffusion coefficients for absorption and desorption runs of a double-sided experiment, but this effect had not been seen for single-sided experiments. The finite difference calculations show that such results are to be expected, and the parameters included in the models that attempt to describe the diffusion process in glassy polymers, such as the dual-mode model, and which lead to concentration-dependent diffusion coefficients, can be found by fitting the experimental data for the double-sided experiment using finite difference modeling. The dependence of the effective difision coefficient on pressure for the single-sided experiment can be correctly predicted using results from the double-sided experiment for an identical sample.