Cellulose/nanoclay composite films with high water vapor resistance and mechanical strength

Cellulose based films were fabricated by dissolving the micro-crystalline cellulose and cotton linter in a LiOH/urea aqueous system, followed by regeneration in acetone. The water vapor transmission rate (WVTR) values of the films were measured and the results indicated that regenerated micro-crystalline cellulose (RMCC) showed lower WTVR than regenerated cotton linter (RCL). WVTR values were proportional to the thickness of samples. The films also exhibited high oil resistance as no fat oil could pass through the RMCC and RCL films even after a week. The RMCC and RCL/natural-montmorillonite nanocomposites (Na-MMT) films were prepared and characterized. The effect of Na-MMT loading on the mechanical, crystallinity and water vapor transmission properties of the nanocomposites was further investigated. Na-MMT loading improved the mechanical properties and decreased the crystallinity of the nanocomposite films. The results indicated partially intercalated nano-layered structures with WVTR as low as 43 g/m(2)/day.