Fabrication of a low surface energy acrylic/melamine clearcoat with enhanced weathering and biological resistances: Investigation of the role of organic UV absorber and nanosilica particles

Improvement of the weathering resistance of an acrylic/melamine clearcoat containing surface active additive for achieving proper biological resistance has been considered in this study. For this purpose, organic UV absorber (Hydroxyphenyl-benzotriazole) and inorganic UV blocker (silica nanoparticles) were used separately and in combination in the clearcoat. The coatings properties were evaluated by gonio-spectrophotometry, UV-vis, tensile, contact angle and Fourier transform infrared spectroscopy (FT-IR) tests before and after exposure to weathering condition. Also, the biological resistance of the coatings against simulated tree gum (Arabic gum) was studied before and after aging. Results revealed significant improvement of the coatings resistance against UV degradation using combination of organic UV absorber and silica nanoparticles. The improved weathering resistance of the coatings in the presence of organic UV absorber and nanosilica resulted in the improvement of the coatings biological resistance against Arabic gum.