In addition, PVP is also widely used as a disintegrant, adhesive, and can also be used for desalination membrane and artificial kidney dialysis diaphragm; In the food and beverage industry, adding insoluble cross-linked PVP to beer and tea beverages can remove polyphenols and excessive tannins in beer and tea beverages, and it does not remain in them, which plays a role in stabilizing the color, ensuring that the flavor of beer and tea beverages remains unchanged for a long time and removing astringency, and is an excellent beverage clarifier and stabilizer; It is widely used in daily chemicals, especially in cosmetics, such as PVP used in hairspray, which has excellent hair fixation. Increases the function of gloss and moisturizing. and does not absorb dust; In the coating industry, the use of PVP's excellent film-forming properties, the use of PVP as a coating agent to produce paint, the film is transparent without affecting the natural color, and the low molecular weight PVP can make the ink.
The ink has good dispersion stability, giving it the performance of not easy to fade; In polymer polymerization reaction, PVP can be used as a thickener in polymer emulsion polymerization, suspension polymerization and other reaction processes, and play a role in improving the performance of resin. With the development of science and technology, PVP has become more and more widely used, and has been applied in high-tech fields such as photosolid resin, optical fiber, laser optic disk, drag reduction material, etc.
Other aspects, such as building materials, metallurgy, steelmaking, electroplating and other fields of application research has also been carried out, it can be said that PVP has penetrated into the national economy and people's lives in all fields. In the 50s of the 20th century, the ISP company in the United States, the GAF company at that time and the BASF company in Germany successively established NVP production lines based on the acetylene method, and then produced various grades of PVP products, so far, these two companies are still the main manufacturers of PVP products. The acetylene method uses acetylene, formaldehyde, hydrogen, etc. as starting materials to undergo catalytic aldehyde addition.
Catalytic hydrogenation, catalytic dehydrogenation ring, ammoniation, alkyne addition and other five steps to synthesize monomer NVP, and then polymerization under certain conditions can obtain PVP of different molecular weights, NVP and other monomers, such as vinyl acetate, acrylamide, etc. copolymerization to obtain copolymer PVP, or add specific cross-linking agents with difunctional groups, such as N, N-methylene bis-acrylamide, etc., cross-linking polymerization reaction to obtain cross-linked PVP. The process needs to be carried out under high pressure and high temperature conditions, with high requirements for equipment, long process flow and huge equipment, which is only suitable for large-scale production and not suitable for the construction of small and medium-sized manufacturers, so so far only BASF in Germany and ISP companies in the United States use this process to produce NVP and PVP products.
