Concentration-induced stress effects in diffusion of vapors through polymer membranes

✍ Scribed by Myungsoo Kim; P. Neogi

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 607 KB
• Volume: 29
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1984.070290302

✦ Synopsis

Missouri 65401

Synopsis

There are two types of anomalous diffusion of vapors in solid polymers which are held to be due to swelling. If the latter is seen as strain, then there must be an accompanying stress which can affect the nature and magnitude of diffusion. The theories of diffusion in polymers are examined in light of the network theory of Larch6 and Cahn. Their formalism is used to solve permeation and sorption in polymer membranes to illustrate the general features of the elastic effects, particularly the time-dependent nature of the solubility. That "anomalous" effects will be present is without doubt, considering the concurrent nature of the added elastic effects. However, the present calculations fail to unearth any behavior similar to the case I1 diffusion. An order of magnitude estimate has been provided which shows that the effects of elasticity are usually significant in rubbery or amorphous glassy polymers where the anomalous effects occur.