Physical ageing of insulating polystyrene from dielectric properties measurements and structural analysis

The present paper reports on an investigation of the dielectric properties of electrical aged insulating polystyrene (PS) material. The surface physicochemical changes were studied using Fourier transformed infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM) and conductivity measurements. Among others, the most salient results concerns the disappearance of the beta-relaxation processes indicating losses in molecular mobility and scissions of trans-trans chains causing formation of carbonyl (C=O) group which is responsible for the oxidation and damage of the specimen surface.