ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The permeability of films to O2, CO2, and H2O vapor is reduced by drawing processes. The permeability data are compatible with the hypothesis that crystallinity reduces permeability because of (1) a decrease in the volume fraction of penetrable amorphous polymer; (2) a lengthening of the diffusion path by impenetrable barriers, presumably crystallites; and (3) a reduction in segmental motion within the amorphous volume. Analysis of the effect of molecular diameter on diffusion rate shows that the segmental motion within amorphous polypropylene regions is less than that in natural rubber.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760030306
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