Polystyrene foams with inter-connected carbon particulate network

New polystyrene (PS)/carbon nanofiber (CNF) and PS/graphite foams with an interconnected honeycomb-like carbon particulate network of CNF or graphite were prepared by first coating the surface of polymer pellets with either CNF or graphite and then conducting batch foaming using carbon dioxide (CO2) as a blowing agent. It was found that the inter-connected honeycomb-like carbon particulate network could significantly reduce the compression yielding of conventional PS foams. With 1 wt% of CNFs or graphite, the PS foams with inter-connected honeycomb-like carbon particulate network were 5-9 times more electrically conductive than foams made of compounded PS nanocomposite with the same carbon particle loading. In addition, the PS foams with inter-connected honeycomb-like carbon particulate network were more thermally conductive and revealed significantly improved thermal stability comparing to foams made of compounded polymer nanocomposites.