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A theory of case II diffusion
journal contribution
posted on 2013-01-10, 15:07 authored by Noreen Thomas, A.H. WindleA theory is proposed to explain the transport behaviour of organic penetrants in glassy polymers in terms
of two basic parameters: the diffusivity of the penetrant, D, and the viscous flow rate of the glassy
polymer, 1/170. The rate controlling process for transport in these systems is considered to be diffusion
of solvent down an activity gradient coupled with time-dependent mechanical deformation of the
polymer glass in response to the swelling stress. The theory combines these two factors and is able to
predict a wide range of observed transport phenomena from Fickian diffusion kinetics at one extreme to
so-called Case II and Super-Case II behaviour at the other. The existence of a sharp front separating
swollen and unpenetrated polymer is shown to result from the concentration dependence of the viscous
flow rate.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Materials
Citation
THOMAS, N.L. and WINDLE, A.H., 1982. A theory of case II diffusion. Polymer, 23 (4), pp.529-542.Publisher
© ElsevierVersion
- NA (Not Applicable or Unknown)
Publication date
1982Notes
This article is closed access.ISSN
0032-3861Publisher version
Language
- en