Polyvinylpyrrolidone (PVP for short) is a water-soluble, nonionic high-molecular polymer, which is produced by the free radical polymerization reaction of N-vinylpyrrolidone (NVP) monomer. Due to its unique physical and chemical properties and biocompatibility, PVP has become a key material in multiple fields such as industry, medicine, food, and cosmetics, and is hailed as a “multifunctional polymer material”.

I. Physical and chemical properties

PVP has extremely strong water solubility. At room temperature, it can be miscible with water in any proportion to form a transparent and stable solution. It is also soluble in polar organic solvents such as ethanol, propylene glycol and glycerol, but insoluble in non-polar solvents such as petroleum ether, benzene and ether. The viscosity of the solution increases significantly with the increase of molecular weight (K value) and concentration, and it is less affected by temperature.

PVP has excellent film-forming property. When the aqueous solution or alcohol solution is dried, it can form a transparent, flexible and smooth film. The film has no odor, is not brittle and cracked, and has good air permeability. The film is non-irritating to the skin and mucous membranes and can be used as a protective layer or carrier material.

PVP has adhesiveness and complexation. It has strong adhesive force and can be used as a binder for natural/synthetic materials. PVP also has good thermal stability, hygroscopicity, and chemical stability.

Ⅱ. Main application

The core application of PVP is “water solubility + adhesiveness + film-forming property + biocompatibility”, and PVP with different molecular weights (K values) correspond to different scenarios:

1. Medical field (the most core application)

PVP is a “multifunctional excipient” in the pharmaceutical industry, conforming to pharmacopoeia standards. Its main uses are:

Tablet binder: Commonly used is K30 (medium molecular weight), which can enhance the fluidity of particles and the formability of tablets, reduce the delay of cracking and disintegration, and is suitable for various tablets such as aspirin and antibiotics.

Film coating material: it forms a transparent and wear-resistant coating film, which can mask the odor of the drug, prevent moisture and control release.

Pharma solubilizers/stabilizers: They increase the solubility of poorly soluble drugs through complexation, or stabilize easily oxidized drugs.

Solid dispersion carriers: Low-molecular-weight PVP can disperse drugs into nanoscale particles, enhancing bioavailability;

2.Cosmetics field

Hair care: High-molecular-weight PVP K90 is used in hair gel and hair wax to form a flexible protective film, which fixes the hairstyle and is easy to clean without being sticky.

Skin care: Medium and low molecular weight PVP K30 is used as a moisturizer and thickener in face creams and lotions to enhance skin moisture and improve product texture.

Makeup: Used in mascara and eyeliner, it enhances the dispersion and adhesion of pigments and prevents smudging.

3. Food field

Food additives: As thickener, stabilizer and clarifying agent, they are used in beverages (fruit juice, beer), baked goods and dairy products.

In beverages: Prevent fruit pulp from settling and enhance the smoothness of the texture;

In baked goods: Improve the extensibility of dough and extend the shelf life of bread and cakes;

In dairy products: Stabilize milk protein and prevent stratification and precipitation.

4. Industrial field

Coatings/inks: As a binder and film-forming agent, it is used in water-based coatings and printing inks to enhance the adhesion, gloss and wear resistance of the paint film.

Textile industry: It is used in dyeing and finishing processes as a dyeing assistant and color fixative to enhance the utilization rate of dyes and the color fastness of fabrics.

Papermaking industry: As a sizing agent and reinforcing agent for paper, it enhances the strength, smoothness and water resistance of paper.

Electronic materials: Used as electrode binder for lithium batteries, photoresist additive, to improve electrode conductivity and photolithography accuracy.

III. Conclusion

PVP is a kind of polymer material with “comprehensive performance and wide application”. The perfect combination of its water solubility, adhesiveness, film-forming property and biocompatibility makes it irreplaceable in the fields of medicine, food, cosmetics and industry. PVP with different K values can precisely match the demands of various scenarios. In the future, with the expansion of modification technologies and high-end fields, the application scope of PVP will be further expanded.