IR laser ablative degradation of poly(phenylene ether-sulfone): Deposition of films containing ether, sulfone, sulfoxide and sulfide groups

Pulsed infrared laser-induced ablation of poly(1,4-phenylene ether-sulfone) (PES) results in the extrusion of SO₂, CO and hydrocarbon molecules and allows deposition of dark solid paramagnetic carbonaceous films that were analysed by FTIR, UV, XP, Raman and EPR spectroscopy and by electron microscopy and revealed as poor in S and containing CO, SO₂, -SO- and C-S-C units. The films show pronounced conjugation of sp²-C atoms and their EPR spectra are sensitive function of the presence of molecular oxygen. The laser process differs from the conventional pyrolysis of PES which yields SO₂ and phenol as major volatile products and a carbonaceous char.