Antioxidants are a class of chemicals that, when present in only a small amount in a polymer system, can delay or inhibit the oxidation process of the polymer, thus Prevents the aging of polymers and extends their service life, also known as “anti-aging agents”.
Antioxidants can be divided into main antioxidants, auxiliary antioxidants and metal antioxidants. Auxiliary antioxidants can be divided into phosphorus antioxidants, thioether antioxidants, and metal purifiers. Today, Kain Chemical will take you to learn about the phosphorus antioxidants among the auxiliary antioxidants:
The biggest feature of phosphorus antioxidants is their synergistic effect with phenolic antioxidants. During the antioxidant process, phenolic antioxidants capture peroxidative free radicals and then produce hydroperoxides (hydroperoxides can automatically undergo thermo-oxidative aging reactions), but phenolic antioxidants cannot decompose hydroperoxides, and phosphorus Antioxidants can decompose hydroperoxides, thereby inhibiting thermal oxidative degradation of plastics.
In addition, phosphorus antioxidants can also improve the color stability of materials and the weather resistance of products:
Plastic products are prone to discoloration under the influence of ultraviolet rays, and the discoloration of plastic additives is much greater than that of the resin itself. Since phenolic antioxidants produce stable phenolic oxygen free radicals, they lead to the accumulation of coloring products, causing discoloration of plastic products. Phosphorus antioxidants can reduce oxidized phenolic oxidants and turn themselves into colorless or white compounds, thereby improving the color stability of the material.
If the stability of the plastic is not good during processing, the hydroperoxide accumulated in the product will become an initiator of photoaging degradation, which is not conducive to improving the quality of the plastic. The weather resistance of the product can be improved by using phosphorus antioxidants and light stabilizers together to improve the weather resistance of the material.
微信扫一扫打赏
