Water Expandable Polystyrene (WEPS) Foams

Water expandable polystyrene (WEPS) is polystyrene containing water cells as blowing agent. Because of environmental problems of volatile hydrocarbons blowing agents, attempts have been made to replace water as blowing agent. Because of different physical properties of water and volatile hydrocarbons, production condition, physical property and the process of EPS and WEPS will be different. In this paper, the methods of synthesis of WEPS and the recent used methods to improve the final properties of the obtained foam including the synthesis of WEPS in the presence of nanoclay and starch are studied.