Thermal degradation mechanism of poly(butylene carbonate)

摘要

Thermal degradation mechanism of poly(butylene carbonate) (PBC) was elucidated by means of ther-mogravimetric analysis (TGA), ~1H nuclear magnetic resonance (~1H NMR) and pyrolysis-gas chromatog-raphy mass spectrometry (Py-GC/MS). The results indicated that there are three main pathways for the thermal degradation of PBC, including unzipping, P-H transfer and decarboxylation reactions. The unzipping reaction can be facilely induced at low temperature of 200 ℃, and all of the three reactions occur at high temperature above 300 ℃ TGA results suggested the thermal stability order: hydroxyl-terminated PBC < acetyl-terminated PBC < methyl carbonate terminated PBC. The hydroxyl end group can induce the unzipping reaction, while methyl carbonate chain-end depresses the occurrence of it.