α-Tocopherol-induced radical scavenging activity in carbon nanotubes for thermo-oxidation resistant ultra-high molecular weight polyethylene-based nanocomposites

Titleα-Tocopherol-induced radical scavenging activity in carbon nanotubes for thermo-oxidation resistant ultra-high molecular weight polyethylene-based nanocomposites
Publication TypeJournal Article
Year of Publication2014
AuthorsDintcheva, NT, Arrigo, R, Gambarotti, C, Carroccio, S, Filippone, G, Cicogna, F, Guenzi, M
JournalCarbon
Volume74
Pagination14 - 21
Date Published2014
ISBN Number00086223 (ISSN)
KeywordsChemical interactions, Infrared spectroscopy, Nanocomposites, Natural antioxidants, Oxidation resistance, Polyethylene-based nanocomposites, Polymer nanocomposite, Radical scavenging activity, Rheological analysis, Thermo-oxidative stability, Thermoanalysis, Ultra-high molecular weight, Ultrahigh molecular weight polyethylenes
Abstract

α-Tocopherol, a natural antioxidant molecule, was physically immobilized on the outer surface of multi-walled carbon nanotubes (CNTs), and the resulting functionalised particles (f-CNTs) were dispersed in ultra-high molecular weight polyethylene aiming at improving its thermo-oxidation resistance. The success of the functionalization was assessed through spectroscopic and thermal analysis, and the influence of the filler on the thermo-oxidative stability of the nanocomposites was investigated through rheological analyses and infrared spectroscopy. We found that the addition of only 1 wt.% of f-CNTs brings about a surprisingly high oxidation resistance, with a five/ten-fold increase of the induction time of the degradation phenomena. Rather than to the inherent stabilizing action of the α-tocopherol, such a notable result is believed to be due to its specific chemical interactions with the CNTs, which could exhibit a considerable radical scavenging activity due to the formation of structural defects on their outer surface. The latter represent acceptor-like localized states, which radically improve the thermo-oxidative resistance of the f-CNTs-based polymer nanocomposites. © 2014 Elsevier Ltd. All rights reserved.

Short TitleCarbon