UV stabilizers can be divided into UV absorbers and hindered amine light stabilizers HALS:
Chemical uv absorbers slow down the degradation process by preferentially absorbing harmful UV radiation and dissipating it as heat.
HALS are very effective stabilizers for polymers, especially polyolefins. They do not absorb UV radiation, but inhibit polymer degradation by scavenging free radicals. HALS will be regenerated rather than consumed during the stabilization process, so it has high efficiency and long life.
This is the last one.