Polystyrene foams with dispersed catalyst for a design of recyclable plastics

The present authors have already reported that barium oxide is the most effective catalyst for the conversion of waste polystyrene into styrene including both monomer and dimer. Around 85 wt. % of waste polystyrene was converted into styrene when it was degraded at 623 K in the presence of barium oxide as catalyst. In this paper, the preparation and the thermal degradation of polystyrene films with dispersed catalyst are described for a design of recyclable plastics for better environment. More than 85 wt. % of the films was degraded into styrene at 623 K without addition of other catalytic compounds. Techniques for foaming the films using either nitrogen or carbon dioxide are discussed. It was found that the polystyrene foams with dispersed catalyst are well converted into styrene when they are simply degraded at 673 K.