At present, the ultraviolet absorbers used in polymer materials mainly include benzotriazoles, benzophenones, salicylates and triazines. Triazine-based UV absorbers have high heat resistance and excellent wash-off resistance compared to benzotriazole-based UV absorbers. Triazine UV absorbers provide excellent protection across the entire UV spectrum and are particularly effective at absorbing short wavelength radiation (UVB). Triazine UV absorbers are commonly used in polyolefins to provide stability throughout high temperature processing with a TGA(10%) of 347°C.
The European Chemicals Agency (ECHA) included four benzotriazole UV absorbers (UV320, UV 327, UV 328, UV 350) in the list of Substances of Very High Concern (SVHC) in 2014 and 2015. Therefore, the use of benzotriazole UV absorbers is strictly limited and is gradually being replaced. The scale of R&D and production of these triazine ultraviolet absorbers is expanding day by day.
Triazine UV absorbers allow polymers to maintain color, gloss and physical properties under long-term UV exposure, and are an effective solution to polymer degradation caused by high-energy light.
Triazine UV absorber has high efficiency (less dosage, good effect), low gloss (making it more widely used), high processing temperature, good compatibility (good dispersion, easy chemical modification of the molecule itself) and excellent broad spectrum (high molar absorption coefficient in UVA and UVB ultraviolet range). These advantages make triazine UV ultraviolet absorbers become the development direction of UV absorbers.
TINTOLL PowerSorb family offers exceptional UV protection to enhance the performance of coatings, plastics and polymers in many advanced applications, preventing degradation such as fading, loss of gloss and surface chalking.
The mechanism of triazine UV absorbers is based on two components:
Conjugated π-electron structures of compounds
Structures capable of hydrogen migration
When the triazine UV absorber absorbs UV rays, the energy of the molecules rises and the NH bonds are broken. The structure is unstable after the hydrogen bond is broken.
The absorbed energy is released as heat, fluorescence or phosphorescence. This energy is not harmful to polymer materials. The molecular structure is restored, so it can repeatedly absorb a large amount of ultraviolet lights.
UV absorbers for polymers are mainly used to reduce the photodegradation of plastics. They protect materials by converting absorbed UV light into low-impact heat and energy through chemical reactions.