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.

متوسط

1 day

التعليمات

Fill and seal the tubes

Use styrene of 92 % purity or better. Fill glass tubes about 0.7 cm wide and 26 cm long to about 4.5 cm (a sixth of the tube) and seal them. Ours: seal in a torch flame (the patent does not say how).

المواد لهذه الخطوة:

ستايرين4.5 مل

الأدوات المطلوبة:

طقم أنابيب زجاجية

موقد بروبان

نظارة واقية من رذاذ الكيماويات

قفازات مطاطية

خزانة أبخرة (بمجرى تصريف)

Heat at 140 °C for 20 hours

Stand the tubes upright with their lower part in an air bath at about 140 °C for 20 hours (ours: a drying oven). Shorter at higher heat: 155 °C 18 h or 165 °C 16 h. Do not go above 175 °C.

الأدوات المطلوبة:

فرن تجفيف

ميزان حرارة مختبري

Cool and break out

Let the tubes cool. The polystyrene comes away from the glass and usually breaks it. Remove the glass and break the clear solid into small pieces: it is very tough and hard to grind.

الأدوات المطلوبة: