Journal ArticleDOI
The mechanism of gas penetration in porous polyarylate films
TLDR
In this paper, the porosity of polyarylate (PA) films with varying porosities was studied for helium, argon, nitrogen and methanol vapours.Abstract:
Penetrability P of polyarylate (PA) films of varying porosities was studied for helium, argon, nitrogen and methanol vapours. The coefficients D and σ have been determined. The PA films produced by pouring solutions on to supports have been found to have a porous structure with closed pores. This conclusion has been based on the finding of much porosity, an independence of P on excess pressure and on 1√M (M is the mol.wt. of the diffusing gas). The transport of the gas through the PA film has been found to be the result of an activated diffusion which has an activation energy of 4–6 kcal/mole; the size of the latter is independent of the porosity. A mechanism of penetration of the gases and vapours through glass-like, polymer films with closed pores is suggested.read more
References
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Journal ArticleDOI
A model for diffusion in a glassy polymer
Wolf R. Vieth,K.J Sladek +1 more
TL;DR: In this article, a new technique for estimating diffusion rates in solid materials from transient sorption data was developed and applied to the diffusion of gases in polymer films, where the analysis applied to solutes which are sorbed according to a particular isotherm: one described by a linear component (Henry's law) and a commonly observed nonlinear component (Langmuir equation).
Journal ArticleDOI
Diffusion of Gases in Polyethylene Terephthalate
TL;DR: In this paper, a model for diffusion in glassy amorphous and crystalline polymers is proposed, assuming that the driving force for diffusion is the concentration gradient of dissolved molecules which are assumed to be in local equilibrium with molecules in the ''holes'' The model predicts that actual diffusion constants and activation energies are larger than those experimentally measured.
Journal ArticleDOI
Kinetics of sorption of methane in glassy polystyrene
TL;DR: In this article, the diffusion rates of CH4 in glassy polystyrene were measured, over a range of temperatures from 25°C to 45°C and pressures from 3 atm. to 30.5 atm, and it was found that polymer micromotions contribute significantly to the diffusion process in a glassy polymer but may be of lower frequency or amplitude than in normally rubbery systems.
Journal ArticleDOI
Gas transport in glassy polymers
Wolf R. Vieth,J. A. Eilenberg +1 more
TL;DR: In this paper, the dual mode sorption model of Vieth et al. was used to test the data, and a comparison was made with previous work on glassy polystyrene.