Innovative epoxy-titania nanocomposites were prepared starting from titania nanoparticles suspended in benzyl alcohol (BzOH) generated by nonhydrolytic sol–gel process from TiCl4. The obtained suspensions were mixed with an epoxy resin (bisphenol A diglycidyl ether, DGEBA) and the formulations were cured in the presence of ytterbium(III) trifluoromethanesulfonate as cationic initiator. The thermally activated cationic ring-opening polymerization produced a three-dimensional network in which the suspend- ing medium BzOH was covalently linked to the epoxy network according to the “activated monomer” mechanism during the propa- gation step. The presence of titania nanoparticles resulted in a reinforcing and stiffening effect due to both their hydrodynamic effect and, most important, a significantly higher cross-linking density of the composite material with respect to the unfilled epoxy resin.
Epoxy resins reinforced with TiO2 generated by non-hydrolytic sol-gel process / Morselli, Davide; Bondioli, Federica; Marco, Sangermano; Ignazio, Roppolo; Messori, Massimo. - In: JOURNAL OF APPLIED POLYMER SCIENCE. - ISSN 0021-8995. - STAMPA. - 131:(2014), pp. 40470-N/. [10.1002/app.40470]