Lactic Acid → Hydroxyacetic acid--2-hydroxypropanoic acid (1/1)

Participants

Reaction Conditions

Reaction Steps

The lactide obtained in Example 2 (19 g) and glycolide (1 g) were put into a 100-ml reaction vessel equipped with a stirrer and a nitrogen-introducing tube. After substitution of nitrogen gas was carried out three times, the mixture was stirred at 150° C. for 3 hours in a stream of nitrogen. To the resulting mixture was added 0.4 g of Baylith 5A [synthetic zeolite (Kurita Water Industries Ltd.) ]*2, and the temperature was raised to 195°±5° C. The pressure was reduced gradually to 20 mmHg over 30 minutes, followed by stirring for one hour. After the pressure was reduced gradually to 1 mmHg over 30 minutes, the mixture was stirred at 195°±5° C. for 9 hours to give lactic acid-glycolic acid copolymer in the molten state. The product was cooled to room temperature to give 14.64 g of white copolymer. The weight-average molecular weight of this copolymer was 73,000.

Provenance & Evidence