Abstract:
Polystyrene is an amorphous polymer, insulated in nature, having good mechanical properties while Polyaniline is a conductive polymer. Blending of such polymers could give new possibilities of wide range of dielectric, thermal and mechanical properties within a single system.
In this study, firstly polymer blends of Polystyrene and polyaniline were prepared by using solution blending method. Amount of Polyaniline was varied from 1wt% to 40wt%. Mechanical, dielectric and thermal properties were investigated using extensometer, impedance analyzer and TGA. It was found that tensile strength and young’s modulus of the PS/PANI blends were increased by 40% and about 200% respectively whereas elongation at break decreases for the blends as compared to the pure PS. Dielectric constant and dielectric loss at 100Hz increased upto the order of 107and 1010 respectively. Increase of about 100oC was observed in the degradation temperature for the PS/PANI blends.
Graphene Nano Platelets (GNP) seems to be very useful material due to its mechanical, dielectric and ablative properties. This material can be used to prepare the polymer nano-composites to enhance significantly the properties of the system. GNPs were coated with insulated PANI and dispersed at various concentrations ranging from 0.1 wt% to 1.0 wt% in the PS/PANI polymer blends using solution casting method. It was found that tensile strength and the modulus increased by 16% and 20% respectively as compared to the PS/PANI blend having 5wt% of PANI (95/5) which was used as a matrix. Dielectric constant slightly increased for the composites as compared to the blend matrix. Hybrid composites were found to give maximum microwave absorption at about 19 GHz which can be used for absorption purposes in that region.
