SBS/CNTs and SBS/CNTs-COOH nanocomposites have been produced and their photo-oxidation behavior has been compared to that of neat SBS. The photo-oxidation process of pristine SBS, assessed by spectroscopical, mechanical, dynamic mechanical and rheological analysis, occurs mainly through crosslinking and oxidation processes. All obtained results show that both CNTs and CNTs-COOH are able to stabilize the SBS against UVB exposure, hindering the crosslinking reactions and slowing down the oxidized species formation. The CNTs stabilizing effect is attributed to their UV-light shielding properties and their radical scavenging activity. The latter, depending on the amount of surface structural defects, is more pronounced for CNTs-COOH and it is responsible for the interruption of the oxidative propagation during SBS degradation.
Acknowledgments
This work has been financially supported by Ministry of University and Research in Italy (MIUR) (cod: RBFR10DCS7_001), FIRB2010 e Futuro in Ricerca, Project title: ‘‘GREENER e Towards multifunctional, efficient, safe and stable ‘‘green’’ bio-plastics based nanocomposites of technological interest via the immobilization of functionalized nanoparticles and stabilizing molecules'’ (cod: RBFR10DCS7_001).
Appendix A. Supplementary data
Supplementary data related to this article can be found at http:// dx.doi.org/10.1016/j.polymdegradstab.2015.04.011.