Mechanical, dielectric and EMI shielding response of styrene acrylonitrile, styrene acrylonitrile/polyaniline polymer blends, upon incorporation of few layer graphene at low filler loadings

The malfunction of electronic devices and many health-related issues may be caused due to electromagnetic interference (EMI) pollution. To overcome this problem a new set of material SAN/PANI/FLG hybrid composite with better EMI shielding properties is prepared using solution casting technique. Conductive polyaniline (PANI) is added (5wt% and 10wt%) to otherwise, an insulative polymer styrene acrylonitrile (SAN). Furthermore, few layer graphene (FLG) is added (0.1-1wt%) to SAN/PANI polymer blends for preparation of SAN/PANI/FLG hybrid composites. The incorporation of PANI in SAN produces a phase separated morphology, whereas graphene appears in sheet like structure. For 0.1wt% FLG/SAN/PANI-10 composite, total shielding effectiveness (SET) is enhanced from 1.1 to 24.3dB (100Hz), mainly due to enhanced dielectric characteristics. However, the maximum increase in tensile strength (49.6MPa) and modulus (1.5GPa) is observed for 0.5wt% FLG/SAN/PANI-5.0 hybrid composite. The increase in dielectric properties and shielding efficiency of SAN/PANI/FLG may be credited to the accumulation of space charges or electric dipoles at the insulator conductor-interface.