Diffusion of saturated hydrocarbons in low density polyethylene (LDPE) films

Authors

  • Abdul-Fattah A. Asfour,

    Corresponding author
    1. Chemical Engineering Department, University of Windsor, Windsor, Ontario, Canada N9B 3P4
    Current affiliation:
    1. Qatar University, P.O. Box 2713, Doha, Qatar
    • Chemical Engineering Department, University of Windsor, Windsor, Ontario, Canada N9B 3P4
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  • M. Saleem,

    1. Chemical Engineering Department, University of Windsor, Windsor, Ontario, Canada N9B 3P4
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  • D. De Kee,

    1. Chemical Engineering Department, University of Windsor, Windsor, Ontario, Canada N9B 3P4
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  • B. H. Harrison

    1. Department of National Defence, Defence Research Establishment Ottawa, Ottawa, Ontario, Canada K1A OZ4
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Abstract

The diffusion coefficients at zero penetrant concentration, D0, of n-heptane, n-heptane, n-octane, n-decane, and 2,2,4-trimethylpentane (TMP) in LDPE were obtained in the range of 25–50°C, using the desorption method. The dependence of D0 on the size and shape of the penetrant is reported. It was found that D0 decreases with increasing penetrant molecule size. The activation energies of diffusion in the temperature range of 25–50°C increase with increasing penetrant molecule size and are independent of temperature. The results are interpreted in terms of the free volume theory and semiquantitative estimates of the free volume parameters are reported.

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