The UV radiation in the atmosphere often leads to photo-oxidation of the polymers because UV photons can be absorbed by various polymers at different wavelengths. Since the energy of these photons in the wavelength range of 290-400 nm is higher than chemical bonding energy, they are capable of breaking the bonds in the polymer structure.
In this regard, UV-stabilizer masterbatches are added to protect various polymers against UV radiation. The performance of this stabilizer is achieved through several different mechanisms:
In the first mechanism which most UV stabilizers act base on this, the masterbatch absorbs the UV beam and then returns it to a lower energy state. Another mechanism is to quench the excited macromolecules via heat release. And finally, the third mechanism is the absorption of free radicals resulted by UV radiation.
Non-protected polymers against UV radiation are usually involved discoloration and yellowing. Additionally, their physical-mechanical properties such as tensile strength and impact strength decreased in by time.
Ciba Polymer is able to provide different UV-stabilizer masterbatches with unique characteristics based on the final application and the environmental conditions of its use. Most of these masterbatches are used in agricultural films, double and single wall pipes as well as automotive components.