What is light stabilizer?

Light stabilizer is an additive for polymer products (such as plastics, rubber, coatings, synthetic fibers).

It can shield or absorb the energy of ultraviolet rays, quench singlet oxygen and decompose hydroperoxide

into inactive substances, It can make polymer Under the light irradiation, the light chemical reaction possibility

can be eliminated or slowed down, and the process of light oxygen can be prevented or delayed, so can

prolong the service life of polymer products.

Damage effect of ultraviolet radiation on polymers

Solar light is a kind of electromagnetic wave. When it passes through space and ozone layer, the radiation

below 290 nm and above 3000 nm are almost filtered out. The actual electromagnetic wave reaching the

ground is 290-3000 nm. Among them, visible light is in the range of 400-800 nm (about 40%), infrared light

is in the range of 800-3000 nm (about 55%) and wave is in the range of 400-800 nm (about 40%). Ultraviolet

radiation is about 290-400 nm long (only 5%).

Ultraviolet radiation in sunlight is the main reason for aging of polymer materials. Ultraviolet radiation accounts

for only about 5% of the sun's light, but it has a lot of energy. After absorbing ultraviolet rays, polymer products

can cause self-oxidation and degradation of polymer, destroy the chemical bonds of polymer, make it break

and cross-link, and lead to vicious changes in appearance and physical and mechanical properties of polymer

products, such as color, strength and life. This process is called Photoredox or photoaging.

Mechanism of Light Stabilizer

Light stabilizers have different functions because of their different structures and varieties. Some can shield,

reflect or absorb ultraviolet rays and convert them into harmless heat energy; others can quench the excited

states of molecules or groups stimulated by ultraviolet rays and make them return to the ground state,

eliminating or slowing down the possibility of Photoredox reaction; others can capture the free radicals

generated by photoredox, from It prevents the free radical reaction leading to the aging of the products and

protects the products from ultraviolet damage.