反应详情

温度

120 °C

The lactic acid oligomer obtained in Example 20 (18.0 g) and 2.1 g of 100% glycolic acid were put in a reaction vessel equipped with a stirrer and a nitrogen-introducing tube. After substitution of nitrogen gas was carried out three times, the materials were molten by raising the temperature by 10° C. perminute up to 120° C. in a stream of nitrogen, followed by addition of 2.1 g of commercially available synthetic aluminum silicate containing 17% aluminum oxide. Then the temperature was raised to 200° C., and the pressure was reduced gradually to 20 mmHg over 30 minutes, followed by stirring at 210±10° C. for 3 hours. After the pressure was reduced gradually to 1 mmHg over 30 minutes, the mixture was stirred at 210±10° C. for 19 hours to give copolymer in the molten state. The product was cooled to room temperature to give 9.8 g of lactic acid-glycolic acid copolymer as a dark brown solid.

1. customequipped with a stirrer
2. additiona nitrogen-introducing tube
3. temperatureThen the temperature was raised to 200° C.
4. waitAfter the pressure was reduced gradually to 1 mmHg over 30 minutes
5. stirringthe mixture was stirred at 210±10° C. for 19 hours
6. customto give copolymer in the molten state
7. temperatureThe product was cooled to room temperature