UV-329 (5411)

UV-329 (5411) by MPI Chemie is an ultraviolet light absorber (UVA) of the hydroxyphenyl benzotriazole class. It is used as a light stabilizer for organic substrates. It can prevent the oxidation, chain fission, uncontrolled recombinations and cross-linking reactions that are caused by photo-oxidation of polymers. It dissipates the absorbed light energy from UV rays as heat by reversible intramolecular proton transfer. UV-329 (5411) reduces the absorption of UV rays by the polymer matrix and hence reduces the rate of weathering.