Diffusion of Penetrants in Polymers

Abstract

Much effort has been expended in trying to understand and predict the unusual phenomena which can occur when initially glassy polymers are exposed to small-molecule gases, organic vapors or liquids. Sorption of the gas or vapor seems to occur at two distinctly different sorption sites (dual mode sorption), and influx of the penetrant leads to a non-Fickian front traveling at constant velocity (case-II diffusion). Because traditional measurement techniques such as sorption and permeation are complicated by these very phenomena which they try to explain, attempts to determine to what extent these very phenomena which they try to explain, attempts to determine to what extent these phenomena are governed by diffusive characteristics of glassy transport rather than by the interplay of diffusion and polymer relaxation have been frustrated. Instead, a method of observing diffusion which does not require penetrant transport across a surface and influx into the sample must be used. (JG)

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Document Details

Document Type
Technical Report
Publication Date
May 07, 1990
Accession Number
ADA223217

Entities

People

  • Matthew Tirrell
  • Theodore S. Frick
  • Timothy P. Lodge

Organizations

  • University of Minnesota

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Classification
  • Coefficients
  • Diffusion
  • Diffusion Coefficient
  • Dual Mode
  • Materials
  • Measurement
  • Military Research
  • Molecules
  • Periodic Variations
  • Polymers
  • Security
  • Small Molecules
  • Sorption
  • Transport Ships

Readers

  • Materials Science and Engineering.
  • Polymer Science and Technology
  • Theoretical Analysis.