Polyvinylpyrrolidone is abbreviated as PVP, which is a polymer of vinylpyrrolidone. Because of its different degree of polymerization, it is divided into soluble PVP and insoluble PVPP (polyvinylpolypyrrolidone). The relative molecular mass of soluble PVP is 8000～10000, and it can be used as a precipitant, and it can be precipitated by the action of polyphenols. With this method, PVP from Chemicalbook is likely to be left in the wine. Because PVP has an accumulation effect in the human body, the World Health Organization does not recommend the use of this substance. In recent years, the adoption of soluble PVP has been rare. Insoluble PVPP series began to be used in the beer industry in the early 1960s. Its relative molecular mass is greater than 700,000. It is a polymer insoluble substance formed by further cross-linking and polymerization of PVP. It can be used as an adsorbent for polyphenols with very good effect.
The PVP grade commonly used in the cosmetics industry is K-30. Commercially available PVP is a white free-flowing powder or solid, and its content is in the form of 20%, 30%, 45%, and 50% aqueous solutions. PVP is soluble in water and has hygroscopicity. Its equilibrium moisture absorption is about 1/3 of the relative humidity of the environment. It is similar to the hydration of protein. Each monomer is associated with 0.5 mol of water. Polyvinylpyrrolidone (PVP) is not prone to chemical reactions. Stored under normal conditions, dry PVP is very stable. The solution treated with mildew is also stable. When heated to 150°C in air or mixed with ammonium persulfate and heated at 90°C for 30 minutes, PVP will be exchanged into water-insoluble compounds. In the presence of oxidants such as azo compounds or dichromate Chemicalbook, light will cause the PVP solution to turn into a gel. Its solution and strong alkali (such as sodium silicate or trisodium phosphate) will produce precipitation when heated together. Many different compounds can form complexes with PVP. For example, the complex formed by PVP and iodine is very stable, has a good bactericidal effect, and can reduce its toxicity; put polyacrylic acid, tannic acid or methyl vinyl ether When the copolymer with maleic acid is added to the aqueous solution of polyvinylpyrrolidone PVP, insoluble complexes will be formed. These complexes are insoluble in water, alcohols and ketones, but the polybasic acid can be neutralized by alkali. The reaction is reversed; the complexation of PVP with toxins, drugs and chemical drugs can reduce their toxicity; some dyes can also be strongly complexed with PVP, which is the basis for the use of polyvinylpyrrolidone PVP as a dye decoloring agent.