Microstructure, thermal and mechanical properties of composite films based on carboxymethylated nanocellulose and polyacrylamide

For attaining eco-friendly nanocellulose-based films with enhanced thermal and mechanical properties, a series of composite films was fabricated by using a facile casting method of aqueous carboxymethylated cellulose nanofibril (c-CNF) dispersions with different contents (0-20 wt%) of polyacrylamide (PAM). The microstructure, thermal and mechanical properties of c-CNF/PAM composite films were investigated as a function of the PAM content. The FT-IR spectra revealed the presence of specific interactions between c-CNF and PAM in the composite films. Accordingly, the mechanical moduli of the films were highly improved with the addition of PAM. The storage modulus of the composite film with 20 wt% PAM were measured to be ˜935 MPa at 30 °C, which was far higher than the modulus ˜17 MPa for the neat c-CNF film. In addition, the thermal decomposition temperatures were found to increase from ˜303 °C for the neat c-CNF film to ˜312 °C for the composite film with 20 wt% PAM.