For plastics, different plastic varieties, due to the molecular structure of the polymer is different, its photoaging degradation mechanism is also different, so in the formulation design, should choose different light stabilizer according to different plastic varieties, such as the selection of several common plastic varieties as follows:
Polyolefin (such as PE and PP) has unstable molecular structure, which is prone to photooxygen aging. In particular, there are tertiary carbon atoms in the molecular structure of PP, which is more prone to aging than PE, especially sensitive to light. In order to inhibit the photooxygen aging of polyolefin products and prolong the service life of products, light stabilizers are often added, such as benzophenones, benzotriazoles, organic nickel complexes and blocked amines. Moreover, the effect is better when combined with blocked phenolic antioxidants and thiobiodipropionate antioxidants. The COMBINATION OF ORGANIC NICKEL COMPLEX QUENCHER AND UV ABSORBENT CAN ALSO play an excellent ANTI-aging effect, AND THE combination OF blocked AMINE free RADICAL TRAPPING agent AND BLOCKED PHENOLIC antioxidant can give the product excellent photostability.
2. When choosing PVC light stabilizer, special consideration should be given to the interaction between them and heat stabilizer. The commonly used light stabilizers in PVC products mainly include benzophenone, benzotriazole, triazine and so on. When metal soap heat stabilizer is used in PVC, UV-P is often used as light stabilizer. When tin thiol is used as heat stabilizer, UV-326 is often used as light stabilizer.