Reaction #2357

Reaction equation

ε-caprolactone

p-dioxanone

propylene glycol

stannous octoate

→

ε-CAPROLACTONE p-DIOXANONE

Solvents

toluene

Conditions

Workup

1. 1
   OtherA flame dried
2. 2
   OtherThe flask was fitted with a flame
3. 3
   Otherdried mechanical stirrer
4. 4
   OtherThe flask was purged with nitrogen three times
5. 5
   Temperaturemaintained at this temperature for about 24 hours
6. 6
   Otherbath temperature was lowered to 110° C.
7. 7
   Temperaturemaintained at this temperature for 24 hours
8. 8
   OtherThe copolymer was dried under vacuum (0.1 mm Hg) at 80° C. for about 32 hours
9. 9
   Otherto remove any unreacted monomer
10. 10
    Otherat 25° C
11. 11
    Otherat room temperature

Procedure

A flame dried, 250 mL, round bottom single neck flask was charged with 57.1 g (0.50 mole) of ε-caprolactone, 51.0 grams (0.50 mole) of p-dioxanone, 3.7 mL (50 mmol) of propylene glycol (USP), and 0.12 mL (34 μmol) of a 0.33M stannous octoate solution in toluene. The flask was fitted with a flame dried mechanical stirrer. The flask was purged with nitrogen three times before venting with nitrogen. The reaction mixture was heated to 140° C. and maintained at this temperature for about 24 hours and then bath temperature was lowered to 110° C. and maintained at this temperature for 24 hours. The copolymer was dried under vacuum (0.1 mm Hg) at 80° C. for about 32 hours to remove any unreacted monomer. The copolymer had an inherent viscosity of 0.22 dL/g in HFIP at 25° C. The copolymer was a liquid at room temperature. The molar ratio of PCL/PDS was found to be 52.4/47.6 by proton NMR.

Source