Sorption and Transport of Water Vapor in Glassy Polyacrylonitrile.

Abstract

Sorption data for H2O in glassy polyacrylonitrile (PAN) are presented for a range of relative vapor pressures at temperatures from 20C to 50C. Simple dual mode sorption, involving 'hole-filling' and molecular solution appears to dominate the low activity region of sorption. Based on the clustering analysis suggested by Zimm and Lundberg, pronounced clustering of penetrant appears to occur above a relative pressure of 0.6. The form of the effective concentration-dependent diffusion coefficient for H2O in PAN, determined by analysis of steady state permeation data, suggests that water in the microvoids and clusters has a lower mobility than the molecularly dissolved water in the polymer matrix. Time lag measurements at high upstream realtive water vapor pressures suggest that the transient state permeation has a non-Fickian character due to relaxations which occur slowly to accommodate the clustering process. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Nov 25, 1978
Accession Number
ADA062793

Entities

People

  • H. B. Hopfenberg
  • M. I. Haider
  • V. Stannett
  • W. J. Koros

Organizations

  • North Carolina State University

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Acrylonitrile Polymers
  • Alkenes
  • Chlorides
  • Clustering
  • Coefficients
  • Diffusion Coefficient
  • Dual Mode
  • Equations
  • Isotherms
  • Military Research
  • Molecules
  • North Carolina
  • Polymers
  • Sorption
  • Steady State
  • Vapor Pressure
  • Water Vapor

Readers

  • Agricultural Chemistry/Soil Science
  • Materials Science (Mechanical Engineering).
  • Polymer Science and Technology