Ethylene Glycol → Lactic Acid

Participants

Reaction Conditions

Reaction Steps

10 g of poly(ethylene glycol) methyl ether (PEG 1,500, Mn=1,500) and 0.2 g of stannous octoate, which is a catalyst, were put into a reactor, and were then dried in a vacuum at a temperature of 110° C. for 4 hours in order to remove moisture therefrom. Subsequently, the dried reactants were cooled, and then 6.0 g of ε-caprolactone (5.576 ml) and 1.43 g of D,L-lactide, which are biodegradable polyester polymer compounds, were added to the dried reactant in a nitrogen atmosphere to form a reaction mixture. Then, the reaction mixture was slowly heated to a temperature of 135° C. in a nitrogen atmosphere and then polymerized for 24 hours to form a reaction product. After the polymerization reaction, the reaction product was cooled to room temperature, and was then dissolved by adding a small amount of methylene chloride thereto. The dissolved reaction product was added to excess ethyl ether and then precipitated to remove unreacted materials therefrom. Then, the reaction product, from which unreacted material was removed, was dried in a vacuum at a temperature of 40° C. for 48 hours, thereby obtaining a triblock copolymer (PCLA-PEG-PCLA) in which hydroxy groups are provided at the ends of the formed poly(ethylene glycol) and biodegradable polyester polymer compound, ε-caprolactone and lactic acid. The yield of the triblock copolymer thus obtained was 91%.

Provenance & Evidence