Barrier Properties of Cellulose Nanocrystals -PVA Nanocomposites

The aim of this study was to investigate the barrier properties of cellulose nanocrystals PVA nanocomposites. Nanocomposite films with different filler loading levels (3, 6, 9 and 12% by wt) were developed by solvent casting method. The effect of cellulose nanocrystals on the barrier properties of the nanocomposites was studied. To this end, moisture absorption, water vapor permeability (WVP), oxygen transmission rate (OTR) and chemical vapor transmission rate (CVTR) of nanocomposite films were measured. The results showed that adding cellulose nanocrystals improve barrier properties, by reduction of the moisture absorption, WVP, OTR and CVTR of nanocomposites. These improvements in the barrier properties of nanocomposites were attributed to the high crystallinity and the strong interactions between the hydroxyl groups of cellulose nanocrystals and PVA chains, indicating that the cellulose nanocrystals were well dispersed and adherent to the PVA matrix. Furthermore, cellulose nanocrystals provide tortuous path for diffusing molecules to pass through the film. Barrier properties improvement in fully hydrolyzed matrices was more significant than partially hydrolyzed matrices.