Thermal degradation mechanisms of polyetherimide investigated by direct pyrolysis MS.

The isothermal pyrolysis of poly(bisphenol A carbonate) (PC) was investigated by matrix-assisted desorption/ionization-time of flight-mass spectrometry. The thermal degradation of the polymer sample was performed at atmospheric pressure. The heat treatment of PC sample for 1/2 hour at 450 °C produced an extensive weight loss and only trace amounts of the pyrolysis were soluble in tetrahydrofuran. The overall structure on the pyrolysis of PC suggested that the PC pyrolysis residue constituted of thermal rearranged sequences which underwent aromatization and crosslinking processes, leading to a graphite-like charred residue as the temperature increases.