ISSN:
0449-2978
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The sorption and diffusion constants of CH2Cl2 at room temperature in quenched polyethylene film drawn at 60°C to different draw ratios λ between 6 and 25 drop drastically between λ = 8 and λ = 9 and then remain nearly constant, dropping only slightly up to λ = 25. Also, the exponential dependence of diffusion constant on concentration of sorbent increases abruptly in the same draw interval and then remains constant at the higher draw ratios. The data may be explained well by a composite madel: a low-permeability fiber structure embedded in a high-permeability spherulitic matrix. As the draw ratio is increased, the initially spherulitic film is gradually transformed into the fiber structure with the transformation being completed between λ = 8 and λ = 9. During subsequent drawing to λ = 25 the mutual arrangement of microfibrils, the basic elements of the fiber structure, changes by longitudinal sliding. However, their transport properties remain nearly constant. The diffusion constant drops a little as a consequence of the increased fraction of tie molecules which reduces the number of unperturbed sorption sites.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1971.160090808
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