Synthesis of novel multifunctional photostabilizers containing UVA and HALS moieties and their effects on polymers and dyes

Ultraviolet absorbers and hindered amine light stabilizers are two kinds of efficient photostabilizers, which have different mechanisms. It is possible to make a synergistic interaction if introducing these two types of photostabilizing fragments into one molecule. In this article, two novel multifunctional photostabilizers UVH‐1 and UVH‐2 containing UVA and HALS fragments were synthesized from a 2‐hydroxyphenylbenzotriazole compound (UV‐P). UVH‐1 was synthesized by a three‐step synthetic strategy via esterification, bromination, and amination. UVH‐2 was facilely synthesized by a one‐step three‐component Mannich reaction. The chemical structure of UVH‐1 and UVH‐2 were confirmed by Fourier‐transform infrared (FTIR), ¹H NMR, ¹³C NMR, and mass spectrometry. Both multifunctional photostabilizers UVH‐1 and UVH‐2 show good ultraviolet absorption performance and excellent light stabilizing effect when applied to photoprotection of dye, polyacrylonitrile, and polyurethane in the solution state, in which UVH‐1 shows better light stabilization performance even on polymers. It can be concluded that a combination of the HALS and UVA active groups can enhance the photoprotective effect on dyes and polymers and also increase the molecular weight of the additive to overcome escape of the photostabilizer from the polymer matrix. J. VINYL ADDIT. TECHNOL., 26:259–267, 2020. © 2019 Society of Plastics Engineers