SO2- and NOx- initiated atmospheric degradation of polymeric films: Morphological and chemical changes, influence of relative humidity and inorganic pigments

The influence of polluting gases on the stability polymeric films has not been studied extensively. In fact, chemical interactions such materials in contact with ambient atmosphere depend different factors as environmental conditions, manufacturing process product, presence additives or various pigments. this study, accelerated artificial gas ageing was carried out. experiments were performed a chamber exposing samples to sulphur dioxide (SO2) and nitrogen oxide (NOx) concentration 15 ppm. relative humidity (RH) content chosen 50% 80% for total 168 h exposure. paint under investigation composed three binding media (acrylic, alkyd, styrene-acrylic) inorganic morphological changes sample surface due impact pollutant investigated using 3D microscope. Moreover, qualitative semi-quantitative analyses by Fourier-Transform Infrared (ATR-FTIR) spectroscopy, focusing degradation reactions mapping evaluation. order fully exploit information these contained ATR-FTIR spectra, multivariate analysis particular, Principal Component Analysis (PCA) enabled verifying main spectral differences between unaged aged samples. Analysis-of-Variance-Simultaneous (ASCA) out understand type, humidity, pigment type deterioration binders.