Structure, morphology, thermal, and electro-magnetic shielding properties of polystyrene microsphere/polyaniline/multi-walled carbon nanotube nanocomposite

Abstract

In this work, polystyrene microspheres (PSMS) and PSMS-based polymer nanocomposites have been prepared. PSMS were first synthesized by dispersion polymerization of styrene monomer. The microsphere- coated-multi-walled carbon nanotube (PSMS/MWCNT) nanocomposite was prepared by incorporating MWCNT into PSMS matrix. Aniline monomer was then introduced by means of in situ oxidative polymerization (PANI) route to PSMS, MWCNT, and PSMS/MWCNT. Fourier transform infrared spectroscopy depicted the composite formation of PANI and MWCNT with PSMS matrix. PANI polymer was successfully polymerized in PSMS matrix and on carbon nanotube walls. According to scanning electron microscopy, all nanocomposites exhibited core-shell morphology. Glass transition temperature (Tg) of PSMS/PANI, PANI/MWCNT, and PSMS/PANI/MWCNT were found as 245℃, 287℃, and 289℃, while maximum decomposition temperature (Tmax) was 387℃, 575℃, and 580℃, respectively. Tetrahydrofuran was shown to be a suitable solvent for dispersing the nanocomposite. Toluene can also be used as suitable solvent for these nanocomposites. X-ray diffraction analysis depicted amorphous form of PSMS; however, PANI and MWCNT reduced the amorphous nature of the microspheres. PANI/MWCNT showed the highest crystallinity among all nanocomposites. Moreover, PSMS/PANI/MWCNT nanocomposite revealed electromagnetic interference shielding effectiveness of ∼23.2 dB.