Improving the performance of UV-curable coatings with carbon nanomaterials

By combining a trifunctional urethane acrylate synthesized from a hexamethylene diisocyanate trimer and caprolactone acrylate with a bifunctional urethane acrylate prepared from hydroxyethyl acrylate and isophorone diisocyanate, a new reactive resin mixture was prepared, and trimethylolpropane triacrylate was chosen as the thinner to constitute a novel coating matrix. Different amounts of multi-functionalized carbon nanotubes (CNTs) and graphene oxide (GO) were introduced into the matrix and cured by ultraviolet radiation, producing different coatings. Utilizing the methods of Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-VIS) spectroscopy, wide angle X-ray diffraction (WAXS) and thermogravimetric analysis (TGA), the chemical structures and physical properties of the coatings were analyzed. A series of ASTM methods, such as pencil hardness classification, RCA abrasion, crosscut adhesion test classification, and chemical resistance rub testing, were applied to investigate the performances of the coatings. It was found that introducing a small amount of carbon nanomaterials can improve the thermal stability, surface hardness, adhesion, abrasive resistance, and chemical resistance performance of the UV-curable coatings. The reasons and mechanisms of the performance improvements are discussed in this work.