Hydrolytic and Thermal Degradation of Random Copolyesters of ε-Caprolactone and 2-Oxepane-1,5-dione

✍ Scribed by Jean-Pierre Latere Dwan'Isa; Philippe Lecomte; Philippe Dubois; Robert Jérôme

• Book ID: 102482926
• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 233 KB
• Volume: 204
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200390092

✦ Synopsis

Abstract

The hydrolytic and thermal stability of random copolyesters of ε‐caprolactone (ε‐CL) and ca. 30 mol‐% 2‐oxepane‐1,5‐dione (OPD) have been investigated. Compared with poly(ε‐caprolactone) (PCL) of a comparable molecular weight, the hydrolytic degradation of the copolyester is faster in a phosphate buffer (pH = 7.4) at 37 °C as confirmed by the time dependence of water absorption, weight loss, melting temperature, and molecular weight. This difference is a result of the higher hydrophilicity imparted to the copolyester by the ketone of the OPD units. The thermal degradation has been studied by thermogravimetric analysis (TGA), ^1^H NMR spectroscopy, and size exclusion chromatography (SEC). The activation energy of the thermal degradation under nitrogen has been found to be lower for the copolyesters than for PCL, which indicates that the OPD co‐units have a deleterious effect on the thermal stability of PCL. The thermal degradation primarily occurs by pyrolysis of the ester functions.

Pyrolysis of the ester function of the ε‐CL/OPD diad.

magnified imagePyrolysis of the ester function of the ε‐CL/OPD diad.