Study on Thermal Degradation of an Amorphous Copolyester by Pyrolysis-Gas Chromatography/Mass Spectroscopy

摘要

Pyrolysis of amorphous copolyester poly(ethylene glycol-co-cyclohexane 1,4-dimethanol terephthalate) (PETG) was investigated at different temperatures from 300°C to 700°C by using pyrolysis-gas chromatography/mass spectroscopy (Py-GC/MS) analysis. The pyrolysis products of PETG has been ascertained. The results showed that some compounds such as benzene, toluene and p-xylene could only be formed above 500°C. During pyrolysis, polymeric chain scission took place as a successive removal of the comonomer units from the polymeric chain. The chain scission was followed by secondary reactions, which produced a variety of compounds. The pyrolysis mechanism of PETG has also been discussed, which is attributed to polymeric chain scission and the secondary reactions such as intramolecular dehydration, rearrangement, cyclization and dissociation of cyclic fragments.