The article presents the influence of ultraviolet radiation on the properties of acrylic coatings. The results of measurements of thickness, hardness, surface roughness Ra parameter values, and specular gloss of the coatings for various aging periods are presented. A decrease in the thickness and gloss of the coatings and an increase in their hardness and roughness were observed.In natural operating conditions, paint coatings are exposed to degradation caused by the destructive effects of ultraviolet (UV) radiation, moisture, heat, and aggressive media. The resistance of paint coatings to the effects of UV radiation depends mainly on the type of film-forming substances used and the special additives applied – photostabilizers.
Solar radiation reaching the Earth’s surface consists of infrared radiation, visible light, UV-A radiation (315 ÷ 400 nm), and a small amount of UV-B radiation (315 nm) [1]. This radiation causes photodegradation of polymer protective coatings.
The process of photodegradation of polymers, including the film-forming substances of paint coatings, consists of initiating radical reactions leading to the shortening of the polymer chain. This process is a direct effect of the absorption of radiation quanta by the functional groups of the polymer [2]. The influence of radiation depends on the wavelength of the light. (…)
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Source: Logistyka Magazine