Method of synthesis of PVP monomer NVP

PVP is widely used as disintegrators, adhesives, and also used in desalination membranes and dialysis membranes of artificial kidney. In the food and beverage industry, adding insoluble cross-linked PVP to beer and tea drinks can remove polyphenols and excessive tannins in beer and tea drinks without remaining in them, which plays a role in stabilizing color, ensuring the flavor of beer and tea drinks remains unchanged for a long time and removing astringency, and is an excellent beverage clarifying agent and stabilizing agent. It is widely used in daily chemical industry, especially in cosmetics, such as PVP used in hair spray, which has excellent hair fixation. Add luster and moisturizing function. And does not absorb dust;

In the coating industry, the use of PVP excellent film formation, using PVP as a coating agent to produce paint, film transparent without affecting the color, low molecular weight PVP can make ink. The ink has good dispersion stability, which makes it not easy to fade. In polymer polymerization,PVP can be used as a thickener for polymer emulsion polymerization, suspension polymerization and other reaction processes to improve resin properties.

With the development of science and technology,PVP has been applied more and more widely, and has been applied in high-tech fields such as photofixing resin, optical fiber, laser optic disc, drag reducing materials, 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 areas.

PVP and its monomer NVP were first synthesized by BASF company J.Alter. Reppe with acetylene as the main raw material, the method is called Reppe method, also known as acetylene method. In the 1950s, ISP company in the United States, At that time, GAF company and Germany’s BASF company have established NVP production lines based on acetylene method, and then produced various grades of PVP products, so far, the two companies are still the main manufacturers of PVP products.

The acetylene process uses acetylene, formaldehyde and hydrogen as starting materials, and undergoes catalytic aldehyde addition. Five steps, such as catalytic hydrogenation, catalytic dehydrogenation into rings, ammonification and acetylene addition, are used to synthesize monomer NVP, and then polymerize under certain conditions to obtain PVP with different molecular weights. NVP can copolymerize with other monomers, such as vinyl acetate and acrylamide, etc., to obtain copolymerized PVP, or add specific cross-linking agents with biffunctional groups, such as N, N-methylene bisacrylamide, etc. Cross-linked PVP was obtained by crosslinking polymerization. Acetylene method due to the use of the main raw material acetylene on the operating conditions are strict, work. The art process needs to be carried out under high pressure and high temperature conditions, with high equipment requirements, long process flow and huge equipment, which is only suitable for large-scale production and not suitable for building medium and small manufacturers, so far only BASF in Germany and ISP in the United States use the process to produce NVP and PVP products.