ISSN:
0098-1273
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
New data are reported for the permeation of inert gases through polyethylene, polytetrafluoroethylene, and silicone and natural rubbers. Additional data are compiled from the literature. The relative solubilities of these gases are practically insensitive to chemical variations in the homopolymer. Hence variations in structure at the glass transition (Tg) and melting (Tm) temperatures that affect diffusion also unambiguously affect permcation. Consequently an equivalence results between permeation at a given temperature for different polymers and permeation at different temperatures for a given polymer. Although the diffusion coefficient changes continuously with temperature, the Arrhenius parameters Do and Ed apparently change discontinuously at Tg and Tm. Their magnitudes and variations with atomic weight reach maxima at about Tg. These data indicate a dependence of the classical correlation between Do and Ed on polymer properties. A perturbed diameter for the permeant, specific for each polymer, is proposed for correlating the Do and Ed data. This correlation makes the changes observed at Tg and Tm more perceptible.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1974.180120109
