Preparation and properties of carboxymethyl cellulose/layered double hydroxide bionanocomposite films

• Caboxymethyl cellulose and layered double hydroxides have attractive potential to develop bio-nanocomposites.
• Increasing layered double hydroxide amount greatly improved mechanical properties of caboxymethyl cellulose films.
• Incorporation of LDH significantly improved water vapor permeability of caboxymethyl cellulose films.
• Relationships between bionanocomposite property and layered double hydroxide amount are reported.

Solution casting method was employed for preparing of carboxymethyl cellulose/layered double hydroxide (CMC–LDH) bionanocomposite films with LDH content ranged from 0 to 8 wt%. The synthesized nanocomposite films were characterized using FTIR, XRD, TEM and SEM analytical methods. XRD and TEM analysis revealed a partially exfoliated structure for nanocomposites with LDH content up to 3 wt%. However, for LDH contents higher than 3 wt%, nanocomposites formed an intercalated structure. Incorporation of LDH significantly decreased water vapor permeability (WVP) of the bionanocomposite films up to 37%. Addition of the LDHs into the CMC matrix is accompanied by a decrease in the film transparency. Mechanical properties of CMC-based films were improved significantly by addition of LDH particles. CMC–LDH nanocomposite film with 3 wt% LDH showed a 148 and 143% increase in the tensile strength and tensile modulus, as well as a 62% decrease in elongation in comparison with the pure CMC film.