Sodium 2,2'-methylene bis (4,6-di-tert-butylphenyl) phosphate is primarily used as a thermal stabilizer in polymers, particularly in polyolefins like polyethylene and polypropylene. It helps to prevent degradation of these materials during high-temperature processing, such as extrusion or molding, by neutralizing acidic by-products and inhibiting oxidative reactions. This chemical is also employed as an antioxidant in lubricants and fuels, where it enhances the longevity and performance of these products by protecting them from oxidation and thermal breakdown. Additionally, it finds application in the production of synthetic rubbers and elastomers, where it contributes to improved heat resistance and durability. Its ability to stabilize materials under harsh conditions makes it valuable in industries requiring high-performance and long-lasting products.