A detailed introduction to polyvinylpyrrolidone PVP

Full name
Polyvinylpyrrolidone. Polyvinylpyrrolidone
CAS No. 9003-39-8
Struction
Quality Specification
K value :88.0 to 98.0
Water content :<5.0%
Forbidden sulfate ash :<0.1%
Aldehyde (acetaldehyde):<0.05%
Hydrazine (PPM):<1.0%
Residual bill :<0.1%
Nitrogen :12.0~12.8%
pH value (10% aqueous solution):5.0-9.0
Heavy metal %(Pb):<10ppm
Peroxide (PPM, hydrogen peroxide):<400
Appearance White or milky white powder or particles
Content (Purity) PVPP
Uses: Used as gas chromatography fixing liquid
Upstream raw materials :1, 4-butanediol, monoethanolamine
Package 25 kg/barrel

Origin
China, Germany, USA I, etc.
Physical Properties
Nature of PVP
polyvinyl pyrrolidone (PVP), a non-ionic polymer, is the most distinctive and widely studied fine chemical variety among N-vinyl amide polymers. Has developed into non-ionic, cationic, anion 3 categories, industrial grade, pharmaceutical grade, food grade 3 specifications, relative molecular mass from thousands to more than one million homopolymer, copolymer and crosslinked polymer series products, and with its excellent unique properties have been widely used.
PVP is divided into four stages according to its average molecular weight size, which is usually expressed by the K value, and different K values represent the corresponding average molecular weight range of PVP. The K value is actually an eigenvalue related to the relative viscosity of PVP aqueous solution, and the viscosity is a physical quantity related to the molecular weight of polymers, so the average molecular weight of PVP can be characterized by K value. Generally, the greater the K value, the greater the viscosity and the stronger the adhesion.
PVP production polymerization
PVP was obtained by bulk polymerization and solution polymerization of vinyl pyrrolidone (NVP) as raw material. In the process of bulk polymerization, due to the large viscosity of the reaction system, the polymer is not easy to diffuse, and the polymerization heat is not easy to remove, resulting in local overheating and other problems, the obtained product has low molecular weight, high residual monomer content, and is mostly yellow, and has no great practical value. Solution polymerization is generally used to synthesize PVP in industry. There are two main routes for the production of PVP polymerization, the first is the solution polymerization of N-2-pyrrolidone (NVP) in organic solvents, followed by steam stripping. The second route is aqueous polymerization of NVP monomer with water-soluble cation, anionic or non-ionic monomer.
PVP homopolymer can be obtained by heating NVP monomer directly to more than 140℃, or adding initiator to NVP solution for heating, or adding initiator to NVP solution (solvent can be water, ethanol, benzene, etc.) through free radical solution polymerization, or directly irradiating NVP monomer or its solution with light. Polymerization methods are different. The structure and properties of the obtained polymers are different, and the composition and structure of the polymers obtained by free radical solution polymerization are more uniform. The performance is also relatively stable, is the most common method of NVP homopolymerization, adjusting the monomer concentration, polymerization temperature, initiator amount and other reaction conditions can obtain different molecular weight and different water soluble PVP homopolymerization.
Process 1: The NVP is configured into a solution with a mass fraction of 50%, and a small amount of hydrogen peroxide is used as a catalyst to initiate polymerization at 50℃ under the action of diisoazo *** prohibition, so that almost all of the NVP is converted into PVP. Then add ammonia water to the polymer to prevent the decomposition of the remaining diisoazo **, monomer polymerization conversion rate of nearly 100%, solid content of 50%.
Process 2: 0.4g dispersant P(NVP-CO-VAC) and 80 g dispersing medium ethyl acetate were added to 250 mL four-way flask, and then dissolved in a constant temperature water bath at 70℃, 20 g monomer NVP and 0.15 g initiator AIBN were added, and the reaction was carried out under nitrogen atmosphere for 6 h, then cooled and filtered. The insoluble substance was dried in a vacuum drying oven for 24h to obtain white PVP solid powder.
The vast majority of PVP polymerization uses AIBN as initiator, and there is no literature on using water-soluble azo initiators to initiate PVP synthesis, but some people are doing work in this area. Since both NVP monomer and PVP are water-soluble, it is entirely possible to use water-soluble azo initiators to initiate polymerization into linear PVP polymers. Moreover, AIBN contains groups that are harmful to human body, and most water-soluble azo initiators do not contain cyanide toxic products and toxic products. PVP is mostly used for products in direct contact with the human body, so water-soluble azo initiators have more advantages than AIBN.

Usage
As a synthetic water-soluble polymer compound, PVP has the general properties of water-soluble polymer compounds, colloidal protection, film formation, adhesion, hygroscopic, solubilization or condensation, but its most distinctive, so people pay attention to its excellent solubility and physiological compatibility. In synthetic polymers such as PVP both soluble in water, but also soluble in most organic solvents, very low toxicity, good physiological compatibility is rare, especially in medicine, food, cosmetics, which are closely related to people’s health in the field, with the reduction of the price of its raw material butyrolactone, will show its good prospects for development. The following is a specific introduction to its application areas:
Medicine and health
PVP has excellent physiological inertia, does not participate in human metabolism, and has excellent biocompatibility, and does not form any irritation to the skin, mucous membranes, eyes, etc. From a biological point of view, the molecular structure of PVP is similar to that of a simple protein model, and even its water solubility, its ability to cooperate with some small molecules, and its ability to be precipitated by some protein precipitators such as ammonium sulfate, limiting words, tannins and phenols are also soluble with proteins. As a result, PVP is widely used as an excipient in pharmaceutical preparations, with specific applications as follows: (1) as a binder in preparations, (2) as a co-precipitant, (3) as a co-solvent or crystallization inhibitor in injection, (4) coating or film forming agent, (5) as a retarder, a controlled release of a drug can extend the action time of the drug (6) artificial vitreum and cornea (7) surgical wrap band (8) PVP iodine disinfectant. In addition, PVP can also be used as colorant and X-ray contrast agent; It can be used in tablets, granules, water and other dosage forms. It has the functions of detoxification, hemostasis, increasing dissolution concentration, preventing peritoneal adhesion and promoting sedimentation rate.
Food processing
PVP itself is not carcinogenic, has good food safety, can form complexes with specific polyphenol compounds (such as tannins), and is mainly used as a food clarifying agent and stabilizer in food processing such as beer, juice, wine.
cosmetics
In the consumption structure of PVP, the cosmetics industry in developed countries accounts for 30% to 50%, and China accounts for 70% to 80%. Because PVP has very low toxicity and physiological inertia, it is not irritating to the skin and eyes, and has a long-term use record in the field of medicine, so it is safe to use in cosmetics. In daily cosmetics, PVP and copolymer have good dispersion and film formation, PVP has a protective colloidal effect in emulsion, can be used in fat and non-fat paste, as a setting liquid, hair spray and mousse setting agent, hair care agent, shampoo foam stabilizer, wave setting agent and hair dye dispersant and affinity agent. Add PVP to cream, sunscreen and hair remover to enhance wetting and lubrication.
Detergent field
PVP has anti-fouling reprecipitation performance, can be used to prepare transparent liquid or heavy dirt detergent, adding PVP in detergent has a good anti-color effect, and can enhance the cleaning ability, washing fabrics can prevent synthetic detergent on the skin stimulation, especially for synthetic fibers, this performance is more prominent than carboxymethyl cellulose (CMC) detergent. PVP can be combined with borax as an effective ingredient in the formulation of phenol-containing disinfectant detergent. The detergent mixed with PVP and hydrogen peroxide has the function of bleaching and killing bacteria.
Textile printing and dyeing
PVP has a good affinity with many organic dyes, and it can be combined with hydrophobic synthetic fibers such as polyphenylene restricted words, esters, nylons and fibrous materials to improve dyeing power and hydrophilicity.
Paints and pigments
PVP coated paint, coating film transparent without affecting the color, improve the gloss and dispersion of paint and pigment, improve thermal stability and improve the dispersion of ink and ink.
Polymer process
Polyvinylpyrrolidone, as a polymer surfactant, can be used as dispersant, emulsifier, thickener, leveling agent, particle size regulator, anti-reprecipitating agent, coagulant, co-solvent and detergent in different dispersion systems.
Other aspects
PVP can be used as a gelling agent for tertiary oil recovery to improve oil recovery rate. As an additive for photosensitive materials, it helps to reduce the emulsibility and enhance the overlay ability of developed images. It is used as thickener, dispersion stabilizer and bond regulator in polymer polymerization. In the paper industry as a dispersant, in acrylamide gasification reaction as a cocatalyst. The application of PVP in separation film, light curing resin, laser video disc, drag reducing coatings, building materials, steel making and electroplating is also rising.