A Review of Thermoplastic Composites Vapour Permeability Models: Applicability for Barrier Dispersion Coatings

摘要

One of the purposes of thermoplastic composites films and barrier dispersion coatings is to minimize the permeation of gases. In both cases, fillers and other additives are added during the film preparation to improve barrier properties. A high level of understanding has resulted from the study of the interaction between filler and polymer phases of thermoplastic composites, and a number of models have been developed to predict the relative permeability of these materials. However, barrier dispersion coatings have not been modelled in this way. The aim of this review was to discuss similarities and differences of thermoplastic composites and barrier dispersion coatings that may influence the applicability of the models for barrier dispersion coatings applied to paper-based materials. The models were developed as a function of the amount of fillers added in thermoplastic composites films and geometrical characteristics of the fillers such as size, thickness, shape and the distribution of fillers in the film. Two- and three-dimensional models with oriented and random arrangement of fillers were presented. Due to the parallel orientation and the similar length and width of fillers used in barrier dispersion coatings, three-dimensional models were more suitable to predict relative permeability. These models assumed plate- or circular-shaped fillers with parallel orientation. In order to prove the models, experimental information was required. Very limited data for barrier dispersion coatings with varying the amount of fillers have been reported in the literature. For this reason, further experiments are required under varied combinations of aspect ratio and the volume fraction of fillers. Copyright (c) 2015 John Wiley & Sons, Ltd.