Electrically conductive green composites based on epoxidized linseed oil and polyaniline: An insight into electrical, thermal and mechanical properties

Renewable resource based electrically conductive composites were prepared using polyaniline (PANI) as a conductive filler and epoxidized linseed oil (ELO) as the matrix. Linseed oil (LO) was epoxidized to form ELO and characterized through 1H NMR and IR spectra. Bio-based ELO/PANI conducting composites were prepared by varying the PANI concentration with an aim of attaining the electrical conductivity in the antistatic range (10−8 to 10−3 S/cm) to replace its petro-based counterpart. Conductivity increased with PANI upto the order of 10−6 S/cm with percolation threshold at around 7% of PANI. The shear stress and viscosity of the uncured ELO resin and ELO/PANI resin mixture were studied as a function of shear rate. Differential scanning calorimetry (DSC) studies showed that addition of PANI had a minimal effect on ELO curing at all concentrations. Dynamic mechanical analysis indicated that PANI as a filler provided mechanical fortification in the rubbery region and increased glass transition temperature (Tg) significantly. Thermal stability of ELO remained almost unaffected with the PANI incorporation. Microscopic observation revealed good distribution of PANI in ELO matrix even at higher loading. Interestingly, tensile strength and Young's modulus increased by ∼8 and ∼27 folds, respectively, at 15% PANI content.