Morphology and functional properties of electrospun expanded polystyrene (EPS)/reduced graphene oxide (RGO) nanofiber composite

Abstract

Conductive polymer nanocomposites are receiving lots of research attention in the field of material science due to their fascinating properties and potentials in many areas of applications. In this work, reduced graphene oxide (RGO); a highly conducting nanofiller was synthesized and incorporated into the matrix of insulating expanded polystyrene (EPS); a recycled polymer, by solution mixing, then electrospun under the effect of optimized processing parameters. A filler loading of between 0.01 and 3 wt% was used at 15% (w/v) concentration of EPS in mixed solvent of DMF and THF to obtain composite nanofibers in submicron range. Analytical tools such as SEM, XRD, FTIR, and RAMAN were used for the investigation of the morphology of the synthesized RGO and electrospun composite nanofibers. Electrical, thermal, and mechanical properties of EPS/RGO composite nanofibers were investigated and compared with that of EPS/Carbon Black composite nanofibers. Keithely 2000 multimeter with four-point probes was used for electrical characterization. A significant drop in resistivity at a very low filler loading of RGO with percolation threshold of 0.7 wt% was recorded for EPS/RGO at conductivity value of 0.132 × 10⁻⁴S/m as compared to percolation threshold of 3.0 wt% obtained from EPS/Carbon Black composite nanofibers. A drastic improvement in thermal stability, Young Modulus, and tensile strength were also observed in all the nanocomposites compared with pure electrospun EPS. A sustainable reuse pathway for post-consumer plastic is also hereby presented.

Keywords:

• Nanofiber composites
• recycled polymer
• functional properties
• percolation threshold

Additional information

Funding

This work was supported by University of Johannesburg Research committee (URC) with National Research Foundation South Africa (NRF SA).