反应详情

温度

281 °C

Dimethyl 3,4'-biphenyldicarboxylate (5.41 g, 0.0200 mole), 21.62 g (0.0800 mole) of dimethyl 4,4'-biphenyldicarboxylate, 18.24 g (0.200 mole) of 1,4-butanediol and 20 μL of titanium tetraisopropoxide are added to a 100-mL round bottom flask equipped with a paddle stirrer, 15-cm heated Vigreux 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 and after the monomers have melted, the stirrer is started. Methanol begins to distill and after 20 minutes, 7.0 mL is collected. During the next 27 minutes, the temperature is increased to 281° C. then the pressure is slowly reduced to 1 mm Hg. The excess 1,4-butanediol distills and viscosity of the reaction mass slowly increases. After an additional 8 minutes, the clear colorless polymer melt becomes very viscous and the polymerization is stopped. As it cools, the polymer melt quickly crystallizes to an opaque white solid which is then ground to a course powder. The polymer's inherent viscosity is 1.16 dL/g and its peak melting point is 266° C.

1. customequipped with a paddle stirrer
2. temperature15-cm heated
3. distillationVigreux 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. distillationto distill and after 20 minutes
9. custom7.0 mL is collected
10. distillationThe excess 1,4-butanediol distills
11. temperatureviscosity of the reaction mass slowly increases
12. customthe polymer melt quickly crystallizes to an opaque white solid which