Dioctyl phthalate (DOP for short), also known as di(2-ethylhexyl) phthalate, chemical formula C24H38O4, CAS number 117-81-7, is a colorless and transparent oily liquid at room temperature and pressure, with a slight ester characteristic odor, low volatility, freezing point of about -55°C, boiling point of about 386°C, and excellent low-temperature fluidity and heat resistance. Slightly soluble in water, easily miscible with most organic solvents such as ethanol, ether, toluene, and mineral oil, and has excellent compatibility with polymer materials such as polyvinyl chloride (PVC), synthetic rubber, and cellulose resins. It has stable chemical properties, good resistance to hydrolysis and aging, and is not prone to decomposition reactions at room temperature. It is the core variety of traditional general-purpose plasticizers. Industrially, it is mainly used in PVC processing (as the main plasticizer) and the rubber industry (as a rubber softener and plasticizer); it is also used in coatings and adhesives (as a plasticizing component), inks (as a plasticizer and solvent), cosmetics (to adjust product texture), and can also be used to prepare cable materials, waterproof materials, etc.