Both UV absorbers and hindered amine light stabilizers (HALS) are used to protect polymers and plastics from degradation caused by light exposure. Although both have similar functions, they work in different ways to provide this protection.
UV absorbers work by absorbing the UV radiation and converting it into heat, which is then released into the surrounding environment. This helps to prevent the UV radiation from penetrating into the polymer structure, and therefore protects the polymer from degradation caused by exposure to UV radiation.
HALS, on the other hand, work by scavenging the free radicals that are generated by light exposure, which can cause the breakdown of the polymer structure. By neutralizing these free radicals, HALS help to prevent the polymer from breaking down, and therefore extend its useful life.
In summary, while UV absorbers primarily protect polymers from UV radiation, HALS protect polymers from the breakdown caused by free radicals generated by light exposure. Both UV absorbers and HALS are important tools in the fight against the degradation of plastics and polymers, and should be used together to provide the best possible protection for these materials.
