Polystyrene: Styrene Polymerised by Heat Alone in Sealed Tubes

Polystyrene is styrene joined into long chains: a tough, glass-clear solid. Heat alone does it. Ostromislensky (US 1,683,402, 1928) sealed pure styrene in glass tubes and held them at 140 °C for 20 hours; hotter goes faster (155 °C 18 h, 165 °C 16 h), but at 175 °C another, unwanted form starts to appear. As it cools the polystyrene shrinks away from the glass and usually breaks the tube. The picture: our diagram.