The performance and durability of UV absorbers (UVAbs) are affected by their inherent chemical efficiency and physical persistence. This paper outlines the structures of UVAbs, the physical mechanism of their activity, involving reversible excitation and deactivation processes, the irreversible processes affected by the microenvironment and reducing UVAbs durability, such as the formation of intermolecular H-tunnels with the polymeric substrate or photoassisted radical oxidation, and physical losses. Structural effects beneficial for their performance, chemical durability and increasing physical persistence are exemplified.
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