Effect of carbon nanotubes on the photo-oxidative durability of syndiotactic polypropylene

Polymer nanocomposites with carbon nanotubes as fillers have attracted more attention than any other nanomaterials. A full development of these materials requires a deep understanding of the way they behave in the use conditions. In this work, the resistance to accelerated photooxidation of syndiotactic polypropylene/multi-walled carbon nanotube (sPP/MWCNTs) films was compared to the photooxidation behaviour of unfilled polypropylene films with the same structural organization. The chemical and structural modifications resulting from photooxidation have been followed using infrared spectroscopy and diffractometric analysis. It was found that a good dispersion degree of the nanofiller, evaluated by atomic force microscopy, contributes to reduction in the rate of photooxidation and an increase in the oxidative thermal stability of the polymeric matrix. Different concomitant effects are considered to explain these results, among which morphology and structure of the nanocomposites together with the MWCNT capacity to interact with oxygen molecules making them unavailable in the first stages of photooxidation.