Polystyrene/multi-wall carbon nanotube composite and its foam assisted by ultrasound vibration

Polystyrene/multi-wall carbon nanotube composite with an interconnected honeycomb-like structure was prepared by firstly coating the surface of the polystyrene pellets with multi-wall carbon nanotube, and sequentially welded through an ultrasound vibration technique. The mechanical and morphological properties of as-prepared composite were investigated in various measurements. It was found that an aggregative and honeycomb-like morphology of multi-wall carbon nanotube existed in the polystyrene/multi-wall carbon nanotube composite according to the polarized optical microscopic and scanning electron microscopic results; the ultrasound vibration could benefit to the performance of flexural strength. Furthermore, different composite foams were studied in this work, employing supercritical carbon dioxide as a blowing agent. Compared to other foams prepared by the conventional methods, the compressive strength of the foams derived from as-described novel method, was significantly improved. Also, being ascribed to this interconnected structure by coating carbon nanotube on polystyrene pellets, good electrical conductivity of 0.05-0.11S/m was achieved in the novel composite foams.