Extrusion foaming of polystyrene/activated carbon/carbon nanoparticles using carbon dioxide/water blowing agent

Extrusion foaming using supercritical carbon dioxide (CO₂) is the most economic and environmentally benign process but it is difficult to control the foam density and maintain the thermal insulation performance. In this study, we added water as a co-blowing agent to better control foam density and introduced carbon nanoparticles/activated carbon (AC) to improve the thermal insulation performance of polystyrene (PS) foam. In order to understand this novel extrusion foaming process, the effects of various parameters such as particle style and content, extruder barrel and die temperatures on foam density, morphology and thermal insulation performance are investigated systematically.