Permeation of carbon dioxide through multiple linear low-density polyethylene films

We have investigated the effect of stacking on the permeation of carbon dio xide through multilayer LLDPE films. The measurements were carried out usin g samples made up of one, two, four, eight and 12 films, respectively, over the temperature interval of 25-85 degrees C. The results indicate that the permeability coefficient P of carbon dioxide does not show any variation o n the number of films stacked. In contrast, the time lag values increase in a non-linear way with increasing the number of films in the samples. The a nalysis of these results, according to gas permeation models through multil ayer systems, shows that boundary effects at the interface between films ar e not found, on the one hand, and the experimental values determined for th e time lags are in good agreement with the theoretical predictions, on the other hand. (C) 2000 Elsevier Science Ltd. All rights reserved.