High-performance UV-curable epoxy acrylate nanocomposite coatings reinforced with aramid nanofibers

Abstract

UV-curing epoxy acrylate (EA) nanocomposite films with different amounts of aramid nanofibers (ANFs) synthesized by a bottom-up method were prepared. The effects of the ANFs on the coating microstructures, curing kinetics, optical light transmittance, mechanical properties, and thermal stability were investigated. Although the ANFs strongly absorb UV light, ANF incorporation did not decrease the final CC bond conversion of the nanocomposites. The UV transmittance of the nanocomposite films decreased dramatically with increasing ANF content, but all films maintained a high visible transmittance. Relative to neat EA, the tensile strength of the 0.05 wt% ANF-reinforced nanocomposites increased by 36%, and the elongation at break of the 0.1 wt% ANF-reinforced nanocomposites increased by 194%. This was mainly attributed to the favorable ANF mechanical properties and their strong interactions (hydrogen bonds and π–π stacking) with EA. This work demonstrates that a small amount of ANFs can enhance the UV-shielding and mechanical properties of UV-curable EA coatings without affecting the transparency or final conversion.