Abstract

Cycloaliphatic epoxy resins containing cationic initiators which are activated by UV radiation give rise to thermoset networks when are exposed to UV light. On the other hand, due to its good mechanical properties, adhesive, thermal stability and electrical insulation epoxy resins are widely used in electrical and electronic applications.The inclusion of ceramic nanoparticles improves the properties of epoxy thermosets, but can influence the curing process. The objective of this work is to study the curing process of nanoparticle dispersions of boron nitride and titanium oxide in a cycloaliphatic epoxy curable epoxy resin. This study has been carried out using photo-calorimetry (UV-DSC) and traditional DSC. The effect of the presence of BN and TiO2 nanoparticles in the ultraviolet curing has been analyzed, finding that the UV curing is not complete, and a subsequent thermal post-curing stage is necessary. It has been found that TiO2 hinders the reaction reaching lower total conversions after both curing stages. Finally, in order to study the thermo-mechanical properties of the nanocomposites, thick specimens were prepared by applying the two stages of UV and thermal curing, the presence of nanoparticles leading to a more heterogeneous specimens. FTIR analysis of curing has shown that the surface of KBr support influences the curing reaction.

Abstract

TiO2 is a semiconductor oxide with many applications due to its properties. To increase the electron transport of the material, it is usually doped with transition metal ions so as not to alter its chemical and mechanical stability and thus be able to use this material for the manufacture of solar cells. In this work, the effect of the incorporation of the Mn dopant on the optical and electrical structures of the TiO2 fims grown by chemical methods under different conditions and deposited by the spin coating technique on glass substrates. Using optical spectroscopy, the influence of the starting precursor, thickness of the fims and the concentration of the dopant was mainly observed with respect to transmittance.