Glycerol → L-lactide epsilon-caprolactone

Participants

Reaction Conditions

Reaction Steps

A flame dried, 250 mL, round bottom single neck flask was charged with 57.1 grams (0.50 mole) of ε-caprolactone, 72.1 grams (0.50 mole) of L-lactide, 4.00 mL (55 mmol) of distilled glycerol, and 0.10 mL (34 pmol) of a 0.33M stannous octoate solution in toluene. The flask was fitted with a flame dried mechanical stirrer. The reactor was purged with nitrogen three times before venting with nitrogen. The reaction mixture was heated to 160° C. and maintained at this temperature for about 18-20 hours. The copolymer was dried under vacuum (0.1 mm Hg) at 110° C. for about 16 hours to remove any unreacted monomer. The copolymer had an inherent viscosity of 0.14 dL/g in hexafluoroisoproponal (HFIP) at 25° C. The copolymer was a liquid at room temperature. The molar ratio of PCL/PLA was found to be 53.7/46.3 by proton NMR.

Provenance & Evidence