Material BehaviourThermal degradation behavior of Copoly(propylene carbonate ε-caprolactone) investigated using TG/FTIR and Py-GC/MS methodologies

Thermal degradation behaviors of copoly(propylene carbonate ε-caprolactone)s (PPCCLs) with different ε-caprolactone (CL) contents were studied at various pyrolysis temperatures by the combination of thermogravimetric analysis/Fourier transform infrared spectrometry (TG/FTIR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) techniques. TGA curves of the copolymers clearly show two stages. The experimental results indicate that the increase of CL content in PPCCL chain leads to an increase of both first and second stage maximum decomposition temperature. The dominant degradation pathway is a backbiting ester interchange reaction involving OH chain ends of PPCCLs, resulting in the formation of cyclic oligomers. In addition, at a relative higher pyrolysis temperature, besides the major products propylene carbonate and caprolactone, some diol and long chain chemicals with ester group were also detected, showing a main intramolecular transesterification accompanied with chain scission decomposition mechanism.