Effect of electron irradiation on polypropylene and polystyrene foils studied by pattern recognition methods on electron spectroscopy data

Abstract

ABSTRACT Degradation of polypropylene (PP) and polystyrene (PS) surfaces under electron beam in ultra-high vacuum is studied by electron spectroscopy, pattern recognition, and atomic force microscopy. Effects on hydrogen, carbon sp2/sp3 content, and microstructure are quantified and correlated. Electron irradiation at 1500 eV causes hydrogen and C sp3 content decrease and surface morphology modification. Roughness changes from 29 to 15 nm on PP, whereas it remains 5 nm on PS. Decreasing C sp3 content in PP, contrary to PS, indicates C–H, C–C bonds scission and carbonization. Cross-linking predominates over carbonization in PS, confirming its better stability, in agreement with surface morphology data.