Preparation and characterization of polylactic acid/polyaniline/nanocrystalline cellulose nanocomposite films

Polylactic acid (PLA) serves as an ideal matrix for preparing electrically conductive materials for electrode, electromagnetic shielding and functional biological material application. Here, an environmentally friendly PLA/polyaniline (PANI)/nanocrystalline cellulose (NCC) nanocomposite film was prepared. Effects of NCC loadings on the rheological behavior of PLA/PANI/NCC suspensions and the microscopic, thermal, mechanical and conductive properties of nanocomposite films were investigated. Results revealed that PLA was wrapped with PANI particles and NCC was uniformly distributed in the obtained nanocomposite films. The PLA/PANI/NCC films exhibited an electrical conductivity of up to 2.16 S∙m^-1 with 1% NCC dosage. Besides, the viscosity and viscoelasticity of the PLA/PANI/NCC suspensions were decreased and the dispersion stability of the suspensions was improved with the incorporation of NCC. Furthermore, the mechanical strength of PLA/PANI/NCC nanocomposite films was significantly improved with the reinforcement effect of NCC. In presence of 4% NCC loading, the tensile strength (TS) and tensile modulus (TM) of PLA/PANI/NCC films had an increase of 38.1% and 89.1%, respectively, while the elongation at break (Eb) exhibited a decrease of 27.3%, as compared to that of PLA/PANI films. These results demonstrated that the as-prepared PLA/PANI/NCC nanocomposite film may have the potential to be used as a bio-based electrically conductive material.