Light stabilizer is a substance that can inhibit or weaken the degradation effect of light on plastics and improve the light resistance of plastic materials. Most of them can absorb ultraviolet rays, so they are also called ultraviolet absorbers. Ultraviolet rays in sunlight are the main reason for the aging effect on polymer materials. Although ultraviolet light only accounts for about 5% of sunlight, its energy is very large, and its energy is enough to break the chemical bonds of polymers, break and crosslink the molecular chains, and cause malignant changes in its mechanical properties. At the same time, its color also changes.
The mechanism of action of light stabilizers varies with their own structure and varieties. Some can shield, reflect ultraviolet rays or absorb ultraviolet rays and convert them into harmless heat energy; some can quench the excited state of molecules or groups excited by ultraviolet rays to return to the ground state, eliminating or slowing down the occurrence of photooxidation Possibility of reduction reaction; some of them capture free radicals generated by photo-redox, thereby preventing free radical reactions that cause product aging, and protecting the product from UV damage.
