Flexible regenerated cellulose/polypyrrole composite films with enhanced dielectric properties

•Flexible RC-PPy composite films were prepared by in situ polymerization.•Incorporation of PPy does not affect the crystalline structure of RC matrix.•Composites exhibited significant improvement in electrical conductivity.•Composite showed high dielectric constant and low dielectric loss. Flexible regenerated cellulose/polypyrrole (RC-PPy) conductive composite films were prepared by insitu polymerization of pyrrole on regenerated cellulose (RC) matrix using ammonium persulphate as oxidant. FTIR, XPS and XRD analysis of RC-PPy composite films revealed strong interaction between polypyrrole (PPy) and RC matrix. XRD results indicated that crystalline structure of RC matrix remains intact even after composite formation. SEM micrographs revealed the formation of a continuous conductive network of PPy particles in the RC matrix, leading to significant improvement in electrical and dielectric properties. The electrical conductivity of RC-PPy composites with 12wt% of PPy was 3.2×10−5S/cm, which is approximately seven fold higher than that of RC. Composites showed high dielectric constant and low dielectric loss values, which is essential in capacitor application.