Objective: In the present work, the possibility of using UV-LED curing processes for the design of
“smart” nanocoatings showing enhanced thermal, thermo-mechanical and barrier properties was thoroughly
Method: A commercially available ethoxylated bisphenol A diacrylate resin, chosen as a model system, was
added to 5 wt.% of an organophilic nanoclay (Cloisite 30B) and a photoinitiator (2,4,6-Trimethylbenzoyldiphenyl-
phosphineoxide), suitable for the UV-LED curing process. The system was then exposed to UV-LED
radiation and the obtained coatings were characterized.
Results: As assessed by infrared spectroscopy and differential scanning calorimetry, a quick exposure (i.e. 5 s)
to the UV-LED radiation in dynamic conditions was enough to achieve the completeness of the photocuring
reaction. The morphology of the obtained coatings was characterized using X-ray diffraction and scanning
electron microscopy: in particular, a clear increase in the interlayer distance was observed, hence indicating the
occurrence of intercalation phenomena of the nanofiller into the curable resin. Furthermore, the good interactions
taking place between the clay nanoplatelets and the polymer network were responsible for: i) an increase
of the glass transition values of the polymer network, ii) enhanced thermal and thermo-oxidative stability of
the nanocoatings and iii) improved barrier properties towards oxygen diffusion.
Conclusion: The UV-LED curing process was found very suitable for obtaining nanostructured coatings showing
decreased oxygen permeability, as well as improved thermal and thermo-mechanical features.