2-ethylhexanoic acid tin(II) salt → Poliglecaprone

Participants

Reaction Conditions

Reaction Steps

A flame dried 500 ml single-neck round-bottom flask is charged with 102.73 gm. (0.90 mole) of ε-caprolactone, 127.68 gm (1.10 mole) of glycolide, 0.228 ml (1.20 mmole/mole of total monomer) of distilled diethylene glycol and 0.135 ml stannous octoate (0.33 molar solution in toluene). The flask is fitted with a flame dried mechanical stirrer and appropriate adapters to provide a closed system. The reactor is purged three times before being vented with nitrogen. The reaction mixture is heated to 190° C. under nitrogen, and maintained at this temperature for about 16 to 18 hours. The copolymer is isolated, ground, and devolatilized (15 hours/110° C./0.1 mm Hg) to remove any unreacted monomers. A weight loss of 2.6% is observed. The inherent viscosity (I.V.) of the copolymer is 1.89 dl/g in hexafluoroisopropanol (HFIP) at 25° C. at 0.1 g/dl. The molar ratio of polycaprolactone(PCL)/polyglycolide(pGA) is found to be 44/56 by NMR. This copolymer has a glass transition temperature (Tg) of -11.9° C., and melting point of 51.9° C. by DSC.

Provenance & Evidence