## Abstract The specific volume of a polyvinyl chloride‐polyvinyl acetate copolymer was studied as a function of temperature. It was found that two second‐order transition temperatures exist, one at 30°C. and the other at 77°C. The lower transition temperature has not been reported previously. Diff
Diffusion of gases and vapors through polyvinyl chloride–polyvinyl acetate copolymer films II. The effect of polymer segment mobility
✍ Scribed by Kumins, C. A. ;Roteman, J.
- Publisher
- John Wiley and Sons
- Year
- 1961
- Weight
- 472 KB
- Volume
- 55
- Category
- Article
- ISSN
- 0022-3832
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✦ Synopsis
Abstract
The minimum free volumes involved in the diffusion of gases of various sizes through a copolymer of polyvinyl chloride–polyvinyl acetate have been calculated by use of equations developed by F. Bueche. It was found that as the gas diameter of the diffusant increased, the minimum free volume for diffusion increased exponentially. Bueche's modification of the Williams, Landel, and Ferry equation permitted use of the diffusion data to determine the number of polymer segments that cooperate in the diffusion process for each particular gas. The internal pressure of the polymer and the energy of activation for viscous flow were also calculated from the gas diffusion data. A discussion of the results is given.
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