PREPARATION AND CHARACTERIZATION OF NANOCOMPOSITE COATINGS OBTAINED THROUGH UV-CURING PROCESSES

This chapter describes the state of the art related to nanocomposite coatings obtained through photopolymerization (UV-curing) processes. Indeed, unlike thermally-induced polymerization reactions, the UV-curing technique can be successfully exploited for preparing nanostructured coatings, limiting the reaggregation phenomena that can involve the used nanofillers and exploiting the advantages of the photopolymerization process, namely: high curing kinetics, high productivity, absence of any solvent (therefore under environmentally-friendly conditions) and energy saving (that is required just for the activation of the reaction process). To this aim, both radical and cationic photocuring mechanisms have been effectively used. The incorporation of nanofillers in UV-curable systems has clearly demonstrated that it is possible to prepare and design novel nanocomposites, which, as an instance, can show enhanced mechanical, thermal, electrical and barrier properties with respect to the unfilled counterparts. In particular, this chapter focuses on the use of several nanofillers showing different aspect ratio, as nanoclays, nanoparticles, carbon nanofillers, et al. The thermal, thermo-mechanical, electrical and barrier properties of these nanocoatings are thoroughly discussed and correlated to the type of nanofillers employed and to the morphology of the nanophases, as assessed by scanning electron microscopy, transmission electron microscopy and X-ray diffraction measurements.