Studies on mechanical, thermal, and barrier properties of carboxymethyl cellulose film highly filled with nanocellulose

Nanocellulose (NC)-reinforced carboxymethyl cellulose (CMC) films were prepared by solvent casting technique. CMC solution in water premixed with NC dispersion at different proportions (i.e. at different NC contents) was used so as to determine the maximum amount of NC that can be incorporated in CMC so as to achieve a film with an optimum combination of mechanical and barrier properties normally sought for packaging applications. The composite films after thorough drying were inspected in respect of its mechanical, thermal, morphological, and water vapor transmission rate characteristics. Incorporation of up to 70 wt% of NC was found to give a practically usable film. A further increase in NC proportion however led to a fragile one. A remarkable increase in tensile strength (in relation to that of CMC) with workable elongation was observed at this maximum dose of NC. Superior thermal and barrier properties of such transparent composite films were also achieved.