THERMAL-DEGRADATION OF POLYMETHACRYLONITRILE

The thermal degradation properties of polymethacrylonitrile (PMAN) hav e been studied by isothermal heating and thermogravimetric analysis. T here are two initiation processes for weight loss from PMAN degraded i n nitrogen, namely chain-end and random scission initiation. There is also an internal cyclization reaction which forms a thermally stable r esidue during the thermal degradation process. The activation energies of the weight loss and formation of stable residues have been calcula ted. X-ray photoelectron spectroscopy has been used to investigate the structure of the stable residue and thus to confirm the degradation m echanism.