How does UV-9 compare with UV-531 and benzotriazole absorbers in polymer applications?

How does UV-9 compare with UV-531 and benzotriazole absorbers in polymer applications?
UV-9 absorbs UV light in the 270-340 nm range with peaks at 285 nm and 325 nm, making it effective for both UV-A and UV-B. Its low volatility and good compatibility suit clear and light-colored plastic products, especially PVC, PMMA, and unsaturated polyester. However, UV-531 (2-hydroxy-4-n-octoxybenzophenone) offers better solubility in polyolefins and lower migration, which is why it dominates in polyethylene and polypropylene films. Benzotriazole types like UV-P and UV-328 provide broader absorption and higher thermal stability for engineering plastics. In China, UV-531 consumption is roughly four times that of UV-9, reflecting the larger polyolefin market versus PVC and cosmetic applications.