Three‐dimensional solubility parameters and chemical protective clothing permeation. II. Modeling diffusion coefficients, breakthrough times, and steady‐state permeation rates of organic solvents in Viton® gloves

Abstract

AbstractThree‐dimensional (3‐D) solubility parameters are used in separate models of the solubility, S, and diffusion coefficient, D, of organic solvents in polymers. Modeled values of these variables are then combined in Fickian diffusion equations to estimate solvent breakthrough times (BT) and steady‐state permeation rates (SSPR). Published data on the permeation of 18 solvents through commercial Viton® glove samples are used to test the accuracy of the approach. Estimates of S are determined based on the model described in the preceding article. Of several empirical correlations investigated to model D, best results are achieved using the product of the solvent molar volume, V1, and either the weighted solvent‐Viton 3‐D solubility parameter difference, Aw, or the Flory interaction parameter, X, also calculated from 3‐D solubility parameters. To account for the change in the value of D over the course of the permeation test, D values are evaluated at breakthrough and steady state. Modeled BT values within a factor of three of experimental values (typically within a factor of two) are obtained for the 15 solvents for which analytical detection limits were reported. Modeled SSPR values within a factor of six of experimental values (typically within a factor of four) are obtained for the 15 solvents with valid SSPR measurements. © 1993 John Wiley & Sons, Inc.