Preparation of Antistatic and Flame-Retardant SDBS-Modified Graphite Nanosheet/Polystyrene Nanocomposites by In Situ Suspension Polymerization

Abstract

Graphite nanosheets with thicknesses of approximately 4 nm and lateral sizes of about 7 μm were facilely prepared through sand-milling exfoliation of expanded graphite powder in an aqueous medium. The resultant graphite nanosheets were oxidized with H₂O₂ and subsequently modified with sodium dodecylbenzene sulfonate (SDBS) to endow them with hydrophobicity. The SDBS-modified graphite nanosheets could be effectively filled into polystyrene microspheres with uniform dispersion via in situ suspension polymerization. The SDBS-modified graphite nanosheet/polystyrene nanocomposite demonstrated excellent antistatic and flame-retardant performance at a remarkably low filler content of 4 wt%. The surface electrical resistance and limiting oxygen index of the nanocomposite were 2.14 × 10⁸ Ω·sq.⁻¹ and 28.2%, respectively. The closely neighboring of graphite nanosheets within the polystyrene matrix reduces electron transfer barriers between nanosheets and constructs effective partitions to suppress the permeation of flammable pyrolyzed gases during combustion, which endows the SDBS-modified graphite nanosheet/polystyrene nanocomposite with enhanced antistatic performance and flame retardancy.