Polyvinylpyrrolidone is a hygroscopic, amorphous polymer supplied as a white, free-flowing powder or a clear aqueous solution. Available in several molecular weight grades, they are characterized by K-value, and used in a great variety of applications. Polyvinylpyrrolidone can be plasticized with water and most common organic plasticizers. It is considered to be physiologically inert:
- Applications take advantage of one or more properties inherent in the polymer, typically due to the lactam ring.
- High polarity and the resultant propensity to form complexes with hydrogen donors, such as phenols and carboxylic acids, as well as anionic dyes and inorganic salts.
- Dispersancy, where components in a mixture are uniformly distributed through the use of polyvinylpyrrolidone.
- Hydrophilicity, where the substantial water solubility of polyvinylpyrrolidone is its dominant feature and frequently a factor along with other properties valuable to numerous applications.
- Adhesion, taking advantage of the higher molecular weight polyvinylpyrrolidones formulating in aqueous media, then evaporating sufficient water to generate a solid product for the desired application.
- Cohesivity, where cohesive strength is achieved through a variety of dry blending and granulation techniques.
Polyvinylpyrrolidone is cross-linkable to a water insoluble, swellable material either in the course of vinylpyrrolidone polymerization, by addition of an appropriate multifunctional comonomer or by post-reaction, typically through hydrogen abstraction chemistry.