FABRICATION OF ELASTOMER BLENDS INVOLVING CORE (POLYSTYRENE)@SHELL (POLYANILINE) APPROACH, THEIR CHARACTERIZATION AND APPLICATIONS IN ELECTROMAGNETIC SHIELDING

Abstract

ABSTRACT Fabrication of rubber blends (EPDM, NBR, and NR) with the polystyrene (PS)-polyaniline (PANI) core-shell (PS@PANI) approach are reported for the first time, and their performance is compared with similar blends prepared by simple individual mixing of PS, PANI, and rubber under identical conditions. It is noted that the unique core-shell morphology accounted for its high surface to volume ratio, leading to the homogeneous dispersion of polyaniline shell and the slow release of polystyrene core into rubber matrix as established by high-resolution transmission electron microscopy. Fourier transform infrared studies show that property enhancement of rubber blends is not significantly affected by the interaction between respective blend components. Conductivity of core-shell rubber blends is found to be relatively higher due to the presence of the interconnected conducting network of PS@PANI within the rubber matrix. These rubber blends also exhibit superior mechanical and thermal properties due to dispersion and slow release of polystyrene core from the polyaniline shell. Electromagnetic interference (EMI) shielding analysis indicated the high shielding efficiency of rubber/PS@PANI blends (∼30 dB: 1–8 GHz) compared to the blends prepared individually from PS, PANI, and rubber (∼18 dB: 1–8 GHz). Such high performance of rubber blends is attributed to the trapping of electromagnetic waves through enhanced internal reflection due to the typical core-shell morphology of PS@PANI. It is anticipated that such low cost, light weight, corrosion resistant and environmentally stable sheets of PS@PANI rubber blends could provide an effective alternative as EMI shielding material for commercial application purposes.