Crosslinked polyethylpyrrolidone (PVPP) is a kind of Chemicalbook crosslinked polymer which is polymerized from vinylpyrrolidone monomer under certain conditions and is insoluble in water, strong acid, strong base and common organic solvents. As an important polymer fine chemical product,PVPP has many excellent and unique properties, and has been widely used in cosmetics, food, medicine and other fields.