反应详情

温度

280 °C

Dimethyl 3,4'-biphenyldicarboxylate (6.00 g, 0.0222 mole), 18.00 g (0.0666 mole) of dimethyl 4,4'-biphenyldicarboxylate, 12.83 g of ethylene glycol and 20 μL of titanium tetraisopropoxide are added to a 100 mL round bottom flask equipped with a paddle stirrer, 15-cm heated Vigreaux column, distillation head, condenser and graduated receiver. The apparatus is evacuated and refilled with nitrogen three times. A molten salt bath preheated to 220° C. is raised around the flask. After 2 hours, the temperature is slowly increased to 280° C. This takes 41 minutes. During this time, 6.9 mL of distillate is collected. Over the next 34 minutes, the pressure is slowly reduced to 1 mm of Hg and the temperature is raised to 321° C. The excess ethylene glycol is distilled. After an additional 10 minutes, the reaction mass is a viscous clear polymeric melt and the polymerization is stopped. As the molten polymer cools, it solidifies to an opaque off-white solid. The polymer is ground to a course powder in a centrifugal mill. Its inherent viscosity is 1.47 dL/g and its peak melting point as determined by differential scanning calorimetry is 280° C.

1. customequipped with a paddle stirrer
2. temperature15-cm heated
3. distillationVigreaux column, distillation head, condenser
4. customThe apparatus is evacuated
5. additionrefilled with nitrogen three times
6. customA molten salt bath preheated to 220° C.
7. temperatureis raised around the flask
8. customThis takes 41 minutes
9. distillationDuring this time, 6.9 mL of distillate is collected
10. customOver the next 34 minutes
11. temperaturethe temperature is raised to 321° C
12. distillationThe excess ethylene glycol is distilled
13. waitAfter an additional 10 minutes
14. customis 280° C.