Polyvinylpyrrolidone PVP application

Polyvinylpyrrolidone (Polyvinylpyrrolidone) is a non-ionic water-soluble polymer, both within the molecule hydrophilic groups, and oleophilic groups, so that it is soluble in water, but also soluble in most organic solvents (such as alcohols, carboxylic acids, amines, halogenated hydrocarbons, etc.), very low toxicity, good physiological compatibility.

The function of polyvinylpyrrolidone

Polyvinylpyrrolidone (PVP) is a versatile ingredient that, according to the Cosmetics Database [1] and CosmeticsInfo.org[2], acts as an adhesive, emulsifying stabilizer, suspension, and hair styling in cosmetics and beauty products. It is found mainly in mascara, eyeliner, conditioner, hair gel, shampoo and other hair care products. It prevents the separation of water and oil in the emulsion and allows the ingredients in the compressed powder to bond together. Polyvinylpyrrolidone also forms a dry film on the surface of skin, nails and hair. When it becomes an ingredient in hair care products, it prevents hair from absorbing moisture and styling hair. It is also used in contact lens solutions and as a thickener in whitening toothpastes and gels for whitening teeth (Wikipedia[3]).

Polyvinylpyrrolidone is approved by the FDA (specifically as a clarifying agent in beer, wine and vinegar, but also as a fresh-keeping coating for citrus fruits) and is also approved by the CIR.

PVP is used in analytical chemistry and catalysts

The aqueous solution of polyvinylpyrrolidone (PVP) can be divided into liquid-liquid or liquid-solid phases in the presence of different amounts of (NH4) 2SO4.

This system is used for the extraction separation of metal ions by organic solvents, and a new extraction system can be obtained. The system has a good

extraction effect for some metal ions, such as PVP- (NH4) 2SO4-H2O system containing PVP20%, using arsine azo (III) as the extraction agent to react in the

solution containing Zr (IV), La (III) ions to form a complex, under certain conditions, The chelate of Zr (IV) and arsine azo has a high extraction rate in the PVP

phase, while the extraction rate of La (III) is very low, so as to achieve the purpose of separating Zr (IV) and La (III). In addition, PVP and some metals

themselves have good complexation, such as PVP and a trace of Cd can be complexed to produce PVP-CD. This property can be used to successfully detect trace

amounts of cadmium. In addition, related studies have reported that for methanol gas phase carbonylation, the activity and selectivity of carbon-supported

collolawrencium catalyst (PVP-RH /C) is much higher than that of simple carbon-supported rhodium catalyst, because the lawrencium collolawrencium catalyst

formed with PVP has narrow particle size distribution, high dispersion and larger specific surface area. The selectivity of the reaction was improved as well as the

catalytic activity.

The application of PVP in special coating

Polyvinylpyrrolidone PVP also known as Povidone (Povidone) is a water-soluble homopolymer polymerized by N-Vinylpyrrolidone (N-Vinylpyrrolidone, referred to as NVP) under specific conditions, with adsorption complexability, physiological compatibility and water absorption and retention properties. These excellent properties of PVP make polyvinylpyrrolidone in cosmetics, food, medicine, industry and other fields have a wide range of application prospects, the application of PVP in special coatings is described below.

The surface of the printing paper is generally coated with an overlay. A transparent coating containing PVP allows the printing ink to dry quickly on it. The transparent layer has good ink absorbency, insoluble in water, and has good coagulability and diffusivity. And high-speed imaging due to transparency. Especially suitable for multi-color ink printing.

PVP can also be used in the preparation of conductive coatings. A conductive plastic film made to prevent electrostatic hazards is made by thinly coating the plastic film with a conductive transparent coating containing carbon black and a binder, and then coating it with a transparent protective layer. PVP is used here as a carbon black binder. In the past, water-soluble polyvinyl acetate alkalinates were used as binders, but satisfactory diluents could not be obtained, and there were problems such as drying difficulty and poor leveling. If PVP is used instead, a conductive coating with good conductivity and transparency, uniform coating and easy drying can be obtained. Generally, the molecular weight of PVP is 10000, because low molecular weight PVP is also beneficial to carbon black dispersion. In addition, if the coating content needs to be increased, it can be adjusted by adding polymer PVP.

The development of technology promotes the expansion of PVP applications

Polyethylpyrrolidone (PVP for short) is a completely synthetic water-soluble polymer compound. It is a series of polymer fine chemical products with excellent properties obtained from monomer N-vinyl pyrrolidone through homopolymerization, copolymerization and crosslinking polymerization. Polyethylpyrrolidone (PVP for short) is a completely synthetic water-soluble polymer compound. It is a series of polymer fine chemical products with excellent properties obtained from monomer N-vinyl pyrrolidone through homopolymerization, copolymerization and crosslinking polymerization. Although PVP products have been available for more than 50 years, it is still one of the few synthetic compounds with good compatibility with human bodies and animals so far. It has excellent solubility, physiological compatibility, complexation, film forming, bonding ability, moisture absorption and other properties, so it has a wide range of important roles in pharmaceutical preparations, biomedicine, cosmetics, food and beverage, detergents and other fields.
In recent years, various emerging industries have greatly promoted the related varieties of PVP series products, as follows:
1, the development of environmental protection water treatment business has a greater demand for PVP products to support membrane separation sewage treatment and water purification treatment process has become the mainstream process of today’s industry, of which nanofiltration, or ultrafiltration PVDF membrane is an important part of the membrane industry, the use of membrane poor-forming agent K30 has been 3000MT/a consumption. With the increasing scarcity of water resources in the world, the increasing economic value of water recycling, and the strengthening of environmental governance in major countries, it is very likely that the use of PVPK30 in the environmental water treatment industry will reach or exceed 10,000 tons in the next 3-5 years.
2, the further development of medical science and technology, the demand for PVP products further increases the known excellent physical and chemical properties of polyethylene pyrrolidone and its excellent physiological compatibility, and its role in pharmaceutical excipients is becoming increasingly important. In addition, PVP and related polymers are being developed by scientists for additional functions on certain drugs. For example, a new type of anti-AIDS drug, PVP and vinyl acetate copolymer (copovidone) in which is an important excipient, but also mentioned a certain drug synergism, so the amount of addition in the drug more than double the addition rate of general excipients.
Development of polyvinylpyrrolidone PVP in environmental protection
The development of environmental protection water treatment business has a greater demand for PVP products to support membrane separation sewage treatment and water purification treatment process has become the mainstream process of today’s industry, among which PVDF membrane with nanofiltration or ultrafiltration is an important part of the membrane industry, and the use of membrane poor-forming agent K30 has been 3000MT/a consumption. With the increasing scarcity of water resources in the world, the increasing economic value of water recycling, and the strengthening of environmental governance in major countries, it is very likely that the use of PVPK30 in the environmental water treatment industry will reach or exceed 10,000 tons in the next 3-5 years. 2, the further development of medical science and technology, the demand for PVP products further increases the known excellent physical and chemical properties of polyethylene pyrrolidone and its excellent physiological compatibility, and its role in pharmaceutical excipients is becoming increasingly important. In addition, PVP and related polymers are being developed by scientists for additional functions on certain drugs. For example, a new type of anti-AIDS drug, PVP and vinyl acetate copolymer (copovidone) in which is an important excipient, but also mentioned a certain drug synergism, so the amount of addition in the drug more than double the addition rate of general excipients.

The application of PVP in wine beverage and food
1. The application of PVP in winemaking
Low alcohol wine brewed from barley, corn, hops, grapes and other plant raw materials, rich in a variety of proteins and polyphenols, these proteins and polyphenols exist in the wine as colloidal particles, when long-term storage or temperature below 0 degrees, higher than 20 degrees may produce flocculating precipitate, resulting in turbidity of the wine, affecting its flavor, some polyphenols are carcinogens. It’s also harmful in liquor. The turbidity phenomenon is especially common in beer, in addition to the turbidity caused by the above-mentioned colloidal particles flocculation, there is also the turbidity phenomenon caused by the ruridity caused by some biological impurities, and the beer will also produce cold turbidity when refrigerated. These are the technical problems that must be solved in the beer production process, otherwise it is difficult to ensure the quality of the wine. The main polyphenols, especially anthocyanins, catechuic acids and flavonoid polyhydroxyl derivatives, which are easy to make beer cloudy and affect its quality, are oxidized to quinones in the air, or polymerized into polymers that are easier to settle, and then precipitated by hydrogen bonding between the hydroxyl group in the molecule and the O atom and the protein molecule. These precipitates are the reasons that affect the stability, color and flavor of beer. To solve this problem, it is necessary to remove the precursors of flocculation precipitation-polyphenols.
In the production, the methods to solve the phenomenon of beer flocculation and precipitation are adsorption filtration, precipitation separation, protease decomposition and so on. Cross-linked PVP (PVPP) is used in beer because it is similar to protein structure, so it is adsorbed and separated from polyphenols. PVP or cross-linked PVP used in brewing is generally insoluble, so it can be easily removed by filtration without remaining in beer.
The steps of PVPP processing beer and rice wine are as follows:
After the beer is treated with diatomite and filtered, the PVPP is added to the beer, stirred for 150~180 minutes, left for 5 minutes and filtered, the filtrate is packaged, the filter residue is regenerated with 1%NaOH solution at 85 degrees, and then washed with 85 degrees hot water to PH 7, the regenerated PVPP can be used.
The company, which is used in the manufacturing of brewing with crosslinked PVP, commodity name PolyFilter, specifications for: PolyFilterVT, PolyFilter10, PolyFilterV. The industrial experiment with a number of domestic breweries has achieved basically the same effect. After PolyFilter treatment, the shelf life of beer can be extended for more than 180 days, and for special beer, the shelf life can be extended for more than 300~360 days.
2. The application of PVPP in non-alcoholic beverages PVPP is not only widely used in beer as a stabilizer, but also a good clarifying agent and stabilizer for tea drinks, juice, vinegar, soy sauce and other liquid foods and health foods. In many cases, because some liquid foods contain a small amount of phenols and polyacids, the placement time is too long will precipitate, and then appear turbidity phenomenon, in the production and processing process as long as the addition of trace PVPP, you can improve their clarification, prevent turbidity phenomenon, and can stabilize the color, improve the taste, extend the storage time.
The application of PVP in daily chemical industry
Due to its excellent surface activity, film forming properties, no irritation to skin and no allergic reaction, PVP has broad prospects for application in the daily chemical industry, especially in cosmetics, skin care products, hair care products and washing products.
The application of PVP in cosmetics:
The research on the application of PVP in cosmetics began in the 1960s, and now it has been widely used in hair care products, skin care products, ornaments and other aspects, among which the most prominent is the application in hair care products. As an excellent surfactant, adding PVP to shampoo can make the foam stable. Because of its physiological compatibility, it will not cause irritation and allergic reactions to the skin, long-term use will not damage the hair, and the hair after washing is smooth and shiny and easy to comb. Hair spray and mousse with PVP have long-lasting styling, good luster, and because PVP has certain water absorption, it makes hair smooth and smooth without appearing dry. PVP for hair care products can be used through the selection and proportion of copolymer monomer types. PVP, which regulates its water absorption and is suitable for dry, neutral and oily hair as a hair conditioner, has unique advantages. The main component of hair is protein, and the molecular structure of PVP is also similar to protein, so it can be used as a supplement for hair nutrients. Long-term use of shampoo and hair care products containing PVP can make hair black and shiny. Reduce split ends.
The role of PVP in other cosmetics is mainly to stabilize the dispersion system such as emulsion and suspension, moisturizing and film-forming role in skin care products, such as PVP in sunscreen, not only moistens, but more importantly, isolates the skin from the sun by forming a film, which plays a role in protecting the skin. In addition, PVP has special uses in other aspects, such as pigment stabilizer, deodorant, deodorant, toothpaste, shaving cream and many other cosmetics.
The application of PVP in washing products
The excellent surface activity of PVP makes it also have a good effect as an ingredient in some washing products. PVPP’s cross-linked polymer PVPP is used as an ingredient in toothpaste, which can not only remove dirt and antifouling, but also have anti-inflammatory and analgesic effects.

PVP acrylic copolymer used in bath not only has the role of dispersion stabilizer, detergent, and sterilization and disinfection function, especially as a medicated soap, soap ingredients used in the summer has a good effect, PVP both oil and water wet properties make it in the cleaning of clothing, especially in the cleaning of hotels, restaurants with tablecloth cleaning agent has a special effect. For example, Guangzhou Jinyuan Detergent products factory with BASF production of “table cloth net” for washing tablecloth, not only washing time is short, washed tablecloth white and soft, there is a light fragrance smell, and both sterilization and disinfection effect.
In summary, the function of PVP in daily chemical products is mainly manifested in the following aspects:
Dispersion stability function, common skin care products, creams and other cosmetics are mostly lotions and suspensions, to make it can be placed for a long time without precipitation deterioration, so that it is dispersed into a uniform system and has a certain stability time is very important, PVP in cosmetics an important function is dispersion stability function.
Decontamination washing function, PVP and its copolymer due to its specific molecular structure, on the one hand has a lipophilic, can remove clothing, hair and skin oil, sweat stains, etc., on the other hand has a good hydrophilicity, so it is easy to wash clothes and skin stains.
Film forming, moisturizing function, which is the most common function of PVP in cosmetics, widely used in hair care products, skin care products and so on.
Sterilization, disinfection function, mainly used in washing products.
The application of PVP in medicine
Using PVP’s good solubility, solubilization, physiological compatibility, bonding ability and complexation ability, it can be used as binder, excipient, coating agent, release agent, co-solvent, germicidal disinfectant, solubilizer, sustained-release agent, capsule shell, dispersion stabilizer, film forming agent and so on in the field of medicine and health. In some developed countries, such as the United States, Germany, Japan, etc., the application of PVP in the field of medicine and health accounts for about 40% to 55% of the total consumption of PVP.
PVP has good bonding properties and strong dissolution ability. The tablets formed by PVP, after being taken in the digestive tract, dissolve quickly at first, so that the tablets locally expand and disintegrate, release drug fragments, and then accelerate the dissolution and absorption of the drugs, and play a rapid role in the efficacy of the drug. PVP is soluble in water and most organic solvents. For these reasons, PVP has been widely used in pharmaceutical tablets, especially in foreign countries, using PVP as a common drug for tablet bonding examples
As follows:
Compound sulfamethoxazole, aspirin, compound aspirin, paracetamol, vitamin C, dipyridamine, dimethyltetracycline, clonidine, benzene sulfonamide, compound analgesic, chewable tablets are illustrated as examples, and their formulations are as follows:
Aluminum hydroxide dry glue 0.4g
Magnesium hydroxide fine powder 0.08g
Powdered sugar 0.02g
Mannitol fine powder 0.2g
10%PVP ethanol (50%) solution 0.03g
Magnesium stearate 0.015g
Peppermint oil 0.0005g
As a drug tablet adhesive PVP is mainly PVP-K30, its dosage depends on the requirements of the mechanical strength of the drug tablet and the nature of the drug itself, generally 0.5% ~ 5%.
Another important use of PVP as drug excipients is co-precipitation agent, some drugs have good efficacy, but its fatal disadvantage is that the solubility in water is very small, resulting in its bioavailability is greatly reduced, the use of some water-soluble substances with these drugs co-precipitation, and then improve the solubility and dissolution rate of drugs, to reduce the dose, improve the efficacy of the effect. As a co-precipitant of insoluble drugs, PVP is being widely used.
The main reason why PVP is used as a drug coprecipitator is that carbonyl O in PVP molecules can be combined with active hydrogen bonds in insoluble drug molecules, which on the one hand makes relatively small drug molecules enter into PVP macromolecules in an amorphous state; on the other hand, hydrogen bonds do not change the water-soluble nature of PVP. As a result, insoluble drug molecules are dispersed in PVP macromolecules through hydrogen bonds, making them easily soluble. The solubility changes of some insoluble drugs after forming coprecipitates with PVP are as follows:
The solubility ratio of drug name to PVP coprecipitate was increased by multiple
Phenytoin 1:52.3
Morpholine 1:538
Reserpine (297-420um) 1:315
The increase of solubility of insoluble drugs in human body also correspondingly improves the bioavailability of drugs. For example, the bioavailability of drugs increased by 1.55 times after phenytoin co-precipitation with PVP, and the increase of solubility after co-precipitation of insoluble drugs was related to the molecular weight of PVP and the amount of PVP. In the case of the same amount (quality) of PVP, the increase rate of drug solubility decreases in the order of PVP-K15>PVPK30>PVPK90, because the solubification effect of PVP itself changes in the order of PVP-K15>PVPK30>PVPK90, and PVP-K15 is generally used more.
The solubility increase of insoluble drugs and PVP coprecipitates varies with the amount of PVP in a complex way. For PVP with a certain molecular weight, the number of molecules of each PVP molecule can bind to is certain, and insoluble drugs often have a certain crystal state. When the amount of PVP is not enough to bind a certain amount of drugs and make them in an amorphous and dispersed state, The drug was still mainly in crystalline state, and the solubility changed little. When PVP must reach a certain content, the drug appears as an amorphous dispersion system, and its solubility can be significantly increased to achieve the purpose of rapid dissolution and absorption. For different drugs, the amorphous dispersed PVP content is not the same as that of PVP co-precipitation, such as 70% of cyclohexamine acetate, and B-carotene, chloramphenicol, dexamethasone, hydroprednisone, streptomycin, tetracycline and testosterone can be increased in human solubility and bioavailability by PVP co-precipitation.
Similarly, the use of hydrogen bond association between PVP molecules and drug molecules can play the opposite effect of solution-increasing and quick-acting, slow release effect, control the degree of association between PVP molecules and drug molecules, and enable drug molecules to be slowly released in the human body after association, delay the dissolution rate, and prolong the effect of drug efficacy. PVP has prolongation effect on penicillin, chloramphenicol, insulin, sodium salicylate, procaine, cortione and other drugs.
In solid drugs, PVP can be used as a binder, solubilizer, disintegrator and delay agent, as well as a drug film coating, drug capsule shell and controlled release film. The drug film coat and capsule shell made of PVP are not easy to break in a dry environment, and the appropriate amount of PVP and other insoluble polymers together make permeable films of different thickness and different pore sizes, which can adjust the rate of drug passing through the film, and then achieve the effect of controlled release.
The application of PVP in liquid drugs
In addition to the many applications of PVP in solid drugs, PVP also plays an important role in injection and ophthalmic medicine. For example, PVP is used in some injections, because of the association between it and drugs, so that one side plays a role in solubility, on the other hand, for some agents that will crystallize or precipitate after too long, PVP can play a role in dispersion and stability. PVP used in ophthalmology can reduce the irritation to the eyes and prolong the action time of ophthalmology.
The application of PVP in binder
PVP has special adhesion to glass, metal and plastic, paper, fabric surface; Coupled with its characteristics of hydrophilicity, dispersion stability, non-thixotropy, thickening, etc., it is widely used in various binder formulations. There are two types of applications. The first is to use PVP as the main component of the adhesive, and the other is to use the adhesive properties of PVP in other products that need binder components, such as coatings, inks, glazing agents, various tablets, granules, sintered materials glaze and so on.

The application of PVP in adhesives
As the main component of adhesives, PVP is the most widely used in industry, such as solid glue sticks, pressure sensitive adhesives and rewet adhesives.
Solid glue stick is a new type of office (including school students) glue, because of its easy to use coating, strong initial adhesion, suitable for all kinds of paper, flat and wrinkly after bonding, to overcome the shortcomings of liquid glue, so nearly 30 years to become the world’s popular office supplies. As a solid glue stick binder should have strong bonding ability, especially good initial adhesion; Good coating, thin and uniform coating; Solid shape, no deformation when the coating is stressed, and can adapt to various climatic conditions; Long storage period, non-toxic. It has been proved that PVP is one of the few varieties that can meet all the above requirements among various water-soluble polymers. There are also solid glues on the market with PVA as the main bonding component, but they are generally difficult to overcome the gelling tendency of PVA, short shelf life, and eventually lose the bonding force. Table 56 compares the adhesion strength of several commercially available solid glue products using PVP as raw material.
The application test proves that the solid glue is suitable for all kinds of writing paper, waxing paper, copy paper, adhesive paper, letterpress printing paper, wrinkle paper, photographic paper, especially for small paper products can operate freely, that is, paste and write; It can also paste fabrics and polystyrene materials such as decorative foam paper. As a result, it has spread rapidly around the world. In the past ten years, China and South Korea have become the main production and export bases of global solid glue. The main raw material PVPK90 purchased by the two countries for the production of solid glue reached about 2,000 tons. For example, China’s Jiangsu Xingda Stationery Group Company purchases PVPK90500-700 tons from home and abroad every year, producing 200-300 million pieces of various types of solid glue, becoming the world’s largest solid glue manufacturer.
Another adhesive with NVP polymer as the main bonding component is a pressure sensitive adhesive. Adding PVP to the pressure-sensitive adhesive formula can improve the initial adhesion, strength and hardness of the tape. The copolymer of acrylate and NVP can be used as a protective film of fine materials, with repeated adhesion and stripping properties. Water-soluble polymers including PVP are widely used as adhesive components for medical skin pressure sensitive adhesives. Especially in the skin drug delivery film, this is a new controlled release drug delivery method. The drug film itself contains the drug that can be absorbed through the skin, and the NVP polymer acts as a binder, becoming a gel-like drug matrix that promotes the diffusion of the drug. The glyceryl nitrate used to treat heart attacks can be used to make such a film. For example, the copolymer of NVP and acrylic ester can be used as a carrier of bactericide iodine, which is fixed on the skin through its pressure sensitive adhesion, and becomes a local anti-infection skin drug administration film. Another type of medical pressure sensitive adhesive is to fix the electrode of the medical device on the skin, it is often a pressure sensitive adhesive can be used repeatedly, and can adsorb the electrolyte solution of the hydrogel, PVP can increase the strength of the hydrogel, improve its stability in the electrolyte.
The third binder with NVP polymer as the main component is the rewet adhesive, the so-called rewet adhesive refers to the dry state does not have bonding, and can play a bonding role in the state of water absorption. PVP, especially PVP/VA, is the main component of this class of binders due to its adjustable hygroscopic properties.
Selecting the appropriate molecular weight of PVP/VA and the ratio of VP to VA in the molecule can improve the flow temperature of the adhesive, the caking

resistance at 75% relative humidity and the sensitivity to water. From the aspects of thermal stability, caking resistance, adhesion, viscosity, mechanical

properties, hygroscopic speed, hygroscopic viscosity and so on, it can meet the requirements of coating, use and storage.
In other products processing, production as a binder application
Because PVP has excellent adhesion to glass, it is used as a glazing agent for glass fibers to make the surface of glass fibers smoother, reduce wear during stretching, and increase the holding force of fiber bundles. Phenolic resin, saturated polyester resin cellulose derivatives, vinyl acetate/methyl methacrylate resin can be combined with PVP to form glass fiber glazing agent. Some formulations have been applied in some large glass fiber factories in China.
According to the same reason, PVP can also be used for the preparation and processing of many inorganic fibers such as carbon fiber, Al2O3 fiber, magnesium titanate fiber, and increase the bonding force of fiber and resin composite.
When glass, ceramics, quartz, asbestos, mica and other inorganic materials are used to prepare highly flexible and special paper, PVP can often disperse and bond the fibers and improve the strength of the paper.
PVP in fine ceramic processing, high dimensional precision sintered ceramics, controlled magnetic sintered ceramics, flexible ceramics, ceramic surface coating, ceramic, glass printing ink, porcelain glaze, nickel plated steel enamel glaze can be used as slurry, pigment dispersant, binder and has been widely paid attention to and applied. In ceramic processing, PVP can be completely burned during sintering. Therefore, there is no effect on the ceramic itself. PVPK90 also prevents the cracking of ceramic products before sintering. In glazes and inks, PVP’s affinity for pigments and dyes ensures uniform, stable and high adhesion of glazes and inks.
PVP is a forming binder for all types of industrial or domestic tablets and granules, such as cleaning tablets for dentures, painting paint tablets for children, sheet and block cleaning agents for household or industrial use.
PVPK30 and PVPK90 are good binders for the manufacture of gypsum bandages. PVP is dissolved in organic solvent such as methanol to generate methanol-pvp solution, the gypsum is dispersed in it, and then the suspension is applied to the bandage. After drying, the gypsum bandages with good plasticity and uniformity can be obtained, which reduces pulverized powder and increases elasticity and fastness.
PVPKl7 can be used as a binder for photographic paper.
All kinds of binder products have their special requirements and conditions of use, as long as the full understanding of the various properties of PVP and their relationships, you can play the bonding role of PVP in the development of many new products.
The global PVP used to produce binders is about 3,300 tons, accounting for more than 7% of the total consumption of PVP. As for the use in the production of various other products, the demand for PVP, which mainly plays a bonding role, is not included in the above data, and it is difficult to correctly count.

The application of PVP in office supplies
With the rapid development of modern science and technology, the continuous improvement of people’s living standards and the rapid development of computer technology, the requirements for all kinds of office paper, printer ribbon, ink, ink and other office supplies are also getting higher and higher. The paper should be white and flat, the ink, ink, etc., requires strong adhesion and non-penetration, thin and not wrinkly, uniform texture and smooth surface, in short, it is necessary to have satisfactory hardness, coating, peeling strength and finish. The ink requires fluent writing, clear and uniform lines, should not precipitate, should not fall off, should not fade, do not block the pen. The requirements for printing ink and coating with magnetic powder ink are higher, because sometimes it is necessary to print plastic products and maintain long-term color proofing, such as ID card production, film copying and so on. In all these office supplies, PVP with different molecular weights showed superior performance.
The application of PVP in ink and ink
PVP has good bonding properties, can be used as a binder, used in ink, ink can make writing and printing handwriting firmly attached to the paper and should not fall off and fade. In addition, PVP has a good dispersion and stability effect on inorganic pigments and organic pigments dispersions, and can be used for ink and ink to obtain a uniform dispersion system, which is not suitable for precipitation, does not block pens and various nozzles, and the depth of writing is uniform. Moreover, PVP is non-volatile, and its role and function are long-lasting, especially if the printing or printing equipment stops running for a long time, it will not block the nozzle, and it has smooth and repeated spray writing performance. PVP for inks and inks is generally PVPK-12 to PVPK-30 products with lower molecular weight.
PVPK-30 is added to the ink and ink to protect the colloid, thicken and increase viscosity, so that the writing is fluent, does not overflow, does not fade, can also reduce the wear of the ball and extend its service life.
The application of PVP in paper and other office supplies
In the paper industry, PVP is used to improve the strength of paper, solubilizing dyes and disperse pigments, and is an important auxiliary in the deinking of waste paper, the decomposition of rags, beating and coloring. When used as a coating, it can improve the gloss, printability and grease resistance of the paper, especially when the surface of the printing paper is coated with a transparent coating containing PVP, which will make the printing ink dry quickly on the paper, the transparent layer has good ink absorption, insoluble in water, has good coagulability, and high-speed imaging because of transparency, especially suitable for multi-color ink printing.
The transparent paper used for drawing is required to have considerable transparency. Since the drawing is often made with pencil, the transparent paper is required to have good adhesion stability to lead powder. The matrix of this paper is transparent cellulose film, which forms transparent crosslinked cellulose sulfate resin with PVP as the main component on the cellulose film. The content of PVP in it is 1% to 10%, forming a transparent skin film of 2-10 microns, which is coated on the matrix cellulose film. On the one hand, the role of PVP in this skin film is to make the skin film and the matrix cellulose film firmly stick together, and at the same time, it also has good adhesion stability for the pigment used in drawing. On the other hand, PVP forms a film with excellent transparent performance, which can make small pigment particles transparent through the skin film and extend the storage time of the drawing, even if there is wear and tear will not affect the integrity of the painted pattern.
Usually used in the use of glue will encounter a lot of inconvenience, only solid paste is solid at room temperature, can be directly wiped and used to overcome the inconvenience of liquid glue or viscous paste, solid paste is usually composed of three different functional substances, namely excipients, solvents and bonding agent resin, the most common bonding agent when polyethylene pyrrolidone (PVP), Using different PVP with molecular weight between 40,000-90000 (K30) and 100,000-13000000 (K90), adjusting the ratio between excipient, PVP and solvent, rod solid pastes with different hardness can be made.
Other water-soluble or water-dispersed polymers such as polyvinyl alcohol, polyacrylamide, polyacrylamide copolymers, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, degradable water-soluble starch, ethoxylated starch, polyvinyl acetate, polyethylenether, polyvinyl chloride, etc. can be used as paste bonding agents. These polymers are not as good as PVP as the adhesive components of pastes (especially solid pastes). As the production cost of PVP decreases, more and more solid glue stick factories use PVP.
Application of polyvinylpyrrolidone PVP as a dispersant binder
The application of PVP in binder, PVP on glass, metal and plastic surface has a special bonding force; Coupled with its characteristics of hydrophilicity, dispersion stability, non-thixotropy, thickening, etc., it is widely used in various binder formulations.
As the main component of adhesives, PVP is the most widely used in industry, such as solid glue sticks, pressure sensitive adhesives and rewet adhesives.
Due to its excellent adhesion to glass, PVP is used as a glazing agent for glass fibers to make the surface of glass fibers smoother, reduce wear during stretching and increase the saturation force of cellulose. Phenolic resin, saturated polyester resin cellulose derivatives, vinyl acetate/methyl methacrylate resin can be combined with PVP to form glass fiber glazing agent. Some formulations have been applied in some large glass fiber factories in China.
PVP can be used as slurry, pigment and other dispersant and binder in fine ceramic processing. In ceramic processing, PVP can be completely burned during sintering. Therefore, there is no effect on the ceramic itself. PVPK90 also prevents the cracking of ceramic products before sintering.
In glazes and inks, PVP’s affinity for pigments and dyes ensures uniform, stable and high adhesion of glazes and inks.
In addition, PVPK30 and PVPK90 are good binders for gypsum binding. PVP is dissolved in organic solvent such as methanol to generate methanol-pvp solution, the gypsum is dispersed in it, and then the suspension is applied to the bandage. After drying, the gypsum bandage with good plasticity and uniformity can be obtained, which reduces the crushing powder and increases the elasticity and fastness.

PVP was used to prepare flake nano silver powder
1. Used for preparing flake nano silver powder
Because of its relatively large surface area and surface contact or wire contact between particles, flake silver nanoparticles have relatively low resistance and good electrical conductivity. In addition, the special surface plasmon resonance properties of flaky silver nanoparticles make them exhibit different optical properties from spherical particles and bulk phase materials. Therefore, flake nano silver powder has great application value in microelectronics, catalysis, surface enhanced Raman, metal enhanced fluorescence, infrared thermotherapy, biomarkers, nano conductive adhesive, electronic packaging materials and other fields. CN201210500911.1 provides a preparation method of flake nano silver powder, which is obtained by the reaction of silver salt aqueous solution containing surfactant and ferrite salt solution at the temperature of 0 ~ 100℃. The silver salts are silver nitrate, silver sulfate or silver acetate. The surfactants are polyethylpyrrolidone (PVP), cetyltrimethyl ammonium bromide (CTAB), sodium dodecyl sulfate (SDS), or polyethylene glycol (PEG). The invention has the following advantages: (1) the method has the advantages of short reaction time, high efficiency and mild reaction condition. (2) The method of the invention has the advantages of simple process and equipment, low production cost, simple operation, green and pollution-free, and is especially suitable for industrial large-scale production.
Second, prepare a graphene/water-based polyurethane conductive composite material
Cn201010613388.x provides a preparation method of graphene/waterborne polyurethane conductive composite material, which mainly uses polyethylpyrrolidone to improve the dispersion and stability of high concentration graphene aqueous solution, and uses a simple and environmentally friendly solution composite method to prepare graphene/waterborne polyurethane conductive composite material. The technical scheme for realizing the invention is as follows: Step 1: prepare graphite oxide by chemical oxidation; The second step: the prepared graphite oxide and polyethylene pyrrolidone are dispersed in an aqueous solution; Step 3: Reduce graphite oxide to graphene by thermal reduction; Step 4: The water-based polyurethane and graphene aqueous solution into a composite material.
Third, a composite material for degradable ureteral stent tube is prepared
Ureteral stent (double pigtail catheter, or D-J tube) is widely used in urology surgery, suitable for upper urinary tract surgery, lithotripsy, dilation of ureteral stenosis and other treatment processes. It can play an important role in draining urine and preventing ureteral stenosis and adhesion blockage after implantation. CN201210538575.X provides a degradable ureteral stent tube and its composite material and preparation method. The degradable ureteral stent tube has smooth surface, good flexibility, controllable degradation fragment shape and degradation rate in line with clinical requirements. A composite material for degradable ureteral stent tubes, in percentage by weight, comprising:
L-lactide / ε-caprolactone copolymer 60% ~ 98%
Crosslinked polyethylene pyrrolidone 2% to 40%.
The beneficial effects of the invention are embodied in: The L-lactide / ε-caprolactone copolymer and cross-linked polyethylpyrrolidone in the composite material used in the ureteral stent tube of the invention are both biomedical composite materials with good biocompatibility, and the degradation time is about 1 to 2 months, which is very suitable for the requirements of urine drainage after surgery, preventing ureteral stenosis, and can degrade and discharge the body without extubation. Reduce the patient’s pain and burden.
Effect of PVP on characteristics of dye-sensitized solar cells
The TiO2 films in photoanodes of dye-sensitized solar cells were prepared by scraping coating of polyvinylpyrrolidone (PVP) as film forming agent. A certain amount of PVP was dissolved in anhydrous ethanol and mixed with 0.5gP25 and other small organic molecules, and then ground to make TiO2 colloidal, which was uniformly coated on conductive glass (film thickness of about 14μm), burned at 450℃ and impregnated with fuel to make TiO2 photoanode. The results show that when other conditions remain unchanged, the optimal amount of PVP is 0.30g, and the photoelectric conversion efficiency of the battery can reach 6.37%.
Dye-sensitized solar cells consist of a semiconductor photoanode, a cathode and a two-stage electrolyte. The semiconductor photoanode is composed of nanocrystalline TiO2 film with many pores adhered to the conductive glass and photosensitive dye adsorbed on the TiO2 particles. Usually, TiO2 is coated on conductive glass using a scratch coating method (i.e. DoctorBlade) or screen printing technology, etc., and then sintered at high temperatures to make it.
The first method is to prepare TiO2 film with polyethylene glycol (PEC) and ethanol system colloid by screen printing. Experiments have found that this technology can not only prevent the cracking of TiO2 film but also maintain high quality porous structure, and the electrical conversion efficiency reaches 5.18% when the film is 17μm.
Another method is to prepare anatase phase TiO2 film (15μm thick) with acetyl acetone, ethanol system colloid and screen printing, and its photoelectric conversion efficiency can reach 4.1%. It can be seen above that the composition of TiO2 slurry has a very significant impact on the battery performance.
Using P25, PVP and anhydrous ethanol as the main components, TiO2 colloid was prepared by scraping and coating method, and TiO2 film about 14μm thick was prepared and assembled. It is found that under the same conditions, changing the amount of PVP has a great impact on the quality of TiO2 film and battery performance.
Through the research experiment, it can be seen that on the one hand, the addition of appropriate amount of PVP can effectively inhibit the agglomeration of TiO2 particles, improve the film formation and uniformity, increase the porosity, and thus increase the adsorption amount of dyes. At the same time, the effective connection between TiO2 particles and the conductive glass is not damaged, and the effective transmission of charge carriers is guaranteed, so as to improve the performance of dye-sensitized solar cells.
Through a large number of experimental analysis, for 0.5gP25 powder, the amount of PVP added should be 0.30g. Too much will block the connection between TiO2 particles, thus hindering the effective transmission of electrons, which is not conducive to the improvement of battery performance; Insufficient results in uneven distribution of pores and serious agglomeration of nano-tio2 electrodes, which will also reduce battery performance.
Therefore, when the PVP content is 0.30g (for 0.50gP25 powder) and the TiO2 electrode thickness is 14μm, the photoelectric conversion efficiency of dye-sensitized solar cells is the highest, which can reach 6.37%. Further optimizing the TiO2 electrode structure, the photoelectric conversion efficiency of the battery has been improved.
PVP is suitable for what kind of membrane pore-causing agent
At present, the more widely used membranes in industry are microfiltration, ultrafiltration, nanofiltration and reverse osmosis membranes, these different types of membranes on the membrane pore size requirements are not the same, polyethylene pyrrolidone PVP as a commonly used pore-forming agent of water treatment membranes, suitable for what kinds of membrane products?
This problem involves the control of membrane pore size structure, many customers will mistake the membrane pore size structure can be controlled solely by the pore-causing agent PVP, in fact, for the membrane pore size (membrane pore size, porosity, porosity, etc.) Especially the membrane pore size structure of ultrafiltration microfiltration membrane is affected and controlled by many factors such as film preparation method, polymer concentration, additive (pore-causing agent), solvent/non-solvent selection, gel bath composition, etc. According to the membrane material and the membrane type to be prepared, after selecting the membrane preparation method, solvent/non-solvent pair, gel bath composition, polymer concentration and other conditions, Adding appropriate molecular weight of pore-causing agent PVP can obtain the desired membrane product with high water flux and large retention rate, and for pore-causing agent PVP, it is very suitable for ordinary ultrafiltration microfiltration membrane products.
As for the reverse osmosis membrane, because most of the reverse osmosis membranes used in the water treatment industry are composite membranes, and in the preparation process of the base membrane, most of the membrane materials used are polysulfone polypropylene and polyacrylonitrile, so the additive PVP is often used as a pore-causing agent, and many domestic companies are also using PVP as a pore-causing agent in the preparation of reverse osmosis membranes.

The appropriate pore-causing agent PVP was selected according to the membrane material
With the continuous development of current membrane separation wastewater treatment technology, the production and use of various types of membranes (ultrafiltration microfiltration nanofiltration reverse osmosis membranes) are increasing, and polyethylpyrrolidone PVP, as an excellent pore-causing agent for water treatment membranes, has also been more and more widely used. It is very important for each enterprise to select the appropriate pore-causing agent according to the membrane material they use for the control of the membrane pore structure of the film forming product.
For ultrafiltration microfiltration membrane, the membrane materials commonly used in the current production are polyvinylidene fluoride PVDF, polysulfone PSF, polyether sulfone PES, polyvinyl chloride PVC, polyacrylonitrile (PAN), polyamide (PA), but the water treatment membrane made directly from these polymer materials has its own defects. For example, the manufacturing cost is high, the mechanical properties are poor, the water flux is small, the film is easy to pollute and damage such defects. As a hydrophilic polymer, PVP added to the casting film solution can not only affect the film forming process from both thermodynamic and kinetic aspects, but also affect and control the pore structure. Unlike other pore-causing agents, PVP will remain in the film forming part, increasing the hydrophilicity of these film products, improving water permeability and stain resistance. In the current film making enterprises, generally PVDF, PSF, PES three membrane materials will often use PVP as a pore-causing agent, for PAN materials, more used is polyethylene glycol PEG as a pore-causing agent, and now with the deepening of research, many enterprises are also using PVP as a pore-causing agent, while adding ferrioxide as a filler in PVP as a pore-causing agent. The film forming effect is also good, PVC material itself due to hydrophobicity in the film production application is limited, but because of its cheap price, convenient materials, this year for PVC film material research is also deepening, such as the Beijing University of Technology to PVC/PVB blend after adding PVP as a pore-causing agent film, the film forming effect is also very good. There are also PVC alloy films produced by Hainan Lisheng, Guangzhou Terui and other enterprises that use PVP as a pore-causing agent. Therefore, most of the membrane materials commonly used by enterprises can use PVP as a pore-causing agent, and now many high-end membrane products, whether foreign or domestic, use PVP as a pore-causing agent, which is also the future development direction of the membrane industry.
Effect of PVP on the performance of PVDF membrane
Polyvinylidene fluoride (PVDF) is a stable hydrophobic material, which has good chemical stability, heat resistance and weather resistance, and excellent mechanical properties. The polymer has been widely used in membrane distillation, osmotic gasification, gas separation, microfiltration, ultrafiltration and other membrane separation fields. However, the surface energy of PVDF is very low and the hydrophobicity is very strong, which makes it difficult for non-solvent (water) to enter the membrane during the film forming process, resulting in delayed phase separation. Therefore, although PVDF has good performance, its film has little application value if there is no suitable additive. In PVP, PEG, PVA, propanol, lithium chloride and other additives, PVP is the most used additive in various formulations. But what is the influence of PVP on the performance parameters of PVDF membrane (membrane mechanical strength, water flux, retention rate, hydrophilicity)?
1. Influence of PVP on the elasticity and mechanical strength of PVDF membrane
In the dry-wet spinning PVDF membrane, the shrinkage rate of the membrane generally increases with the increase of the content of PVP. The addition of PVP in the casting film liquid greatly increases the viscosity of the solution, and the macromolecular substances have a higher orientation during the flow in the spinneret hole, and also have a higher orientation on the inner wall of the film, so the film will shrink to a certain extent during the drying process. The higher the concentration of PVP, the greater the viscosity of the casting liquid, the greater the orientation of the film, the higher the shrinkage during drying.
The strength of the film decreases first and then increases with the increase of the content of PVP, which is related to the thickness of the sponge layer structure of the film section. When PVP concentration is low, the thermodynamic properties of the liquid system in the film forming process control the film forming process, the phase separation speed accelerates with the increase of PVP concentration, and the development of macroporous structure becomes more adequate. However, when PVP concentration increases to a certain extent, kinetic diffusion plays a leading role in the film forming process and becomes a controlling factor. With the increase of PVP concentration, the viscosity of the liquid system of the casting film increases correspondingly, resulting in the increase of the solvent-non-solvent exchange resistance, and the transition of the casting film liquid system from instantaneous liquid-liquid separation to delayed liquid-liquid phase separation, so the development of large pores in the film is inhibited. With the increase of PVP content, the penetration of finger holes in both inner and outer walls of the membrane increased, and the thickness of the spongy structure decreased.
2. The influence of PVP on the water flux and retention of PVDF membrane
Generally, with the increase of the content of PVP, the water flux of the film increases first and then decreases, and the retention rate decreases first and then increases. There is an optimal value of about 5% of the addition amount (the amount of film forming conditions is slightly different). As a good pore-causing agent, PVP mainly affects the membrane pore structure from two factors: thermodynamics and kinetics. When the content of PVP in the casting liquid is low, the influence of thermodynamic factors becomes the dominant factor. The addition of PVP reduces the thermodynamic stability of the casting liquid system and the gel rate is faster. The looser the structure of the membrane, the higher the porosity, the higher the water flux, and the lower the retention rate. However, when PVP increased to a certain extent, the viscosity of the liquid system of the cast film increased with the increase of PVP concentration, resulting in the increase of solvent-non-solvent exchange resistance, the influence of kinetic factors became dominant, the development of finger pores in the film was inhibited, the water flux decreased, and the retention rate increased.
3. The influence of PVP on the hydrophilicity of PVDF membrane
The additive PVP is a kind of hydrophilic polymer material, which can significantly improve the pore structure of the film, and often because part of PVP remains in the film, the hydrophilicity of the film will be improved to a certain extent. If PVP can remain in the film for a longer time, the hydrophilicity of the film can be solved to a greater extent, which is also our membrane specific pore-causing agent GC-PVP-M.
Application of polyvinylpyrrolidone (PVP) in water treatment
Polyvinylpyrrolidone (Polyvinylpyrrolidone) is a non-ionic water-soluble polymer, both within the molecule hydrophilic groups, and oleophilic groups, so that it is soluble in water, but also soluble in most organic solvents (such as alcohols, carboxylic acids, amines, halogenated hydrocarbons, etc.), very low toxicity, good physiological compatibility.

Polymer pore-forming agent
1) Overview
The membrane can be divided into microfiltration, ultrafiltration, reverse osmosis, dialysis membrane, osmotic gasification membrane, gas separation membrane and ion separation membrane. The mechanism of microfiltration and ultrafiltration is sieve processing, and the other is dissolution diffusion mechanism. According to the structure, it can be divided into two kinds: symmetric membrane and asymmetric membrane. At present, there are mainly phase transformation method, melt drawing method, track etching method and sintering method of inorganic film. Phase transformation is one of the most widely used methods for preparing microfiltration and ultrafiltration membranes. The phase transformation method is to prepare a homogeneous polymer solution of a certain composition, and change the thermodynamic state of the solution by a certain physical method, so that it will phase separation from the homogeneous polymer solution, and finally transform into a three-dimensional macromolecular network gel structure. This three-dimensional network of macromolecular gel is the separation membrane.
According to the different thermodynamic properties of the changed solution, the phase transformation method can be divided into solvent evaporation phase transformation method, thermal phase transformation method, vapor deposition phase transformation method and immersion precipitation phase transformation method. The immersion precipitation phase conversion method is the simplest preparation process, and can better regulate the properties and structure of the membrane, and is the most widely used method for preparing ultrafiltration and microfiltration. The membrane interception molecular weight of the ultrafiltration membrane is 1000-100000.
2) Factors affecting film properties
The composition of casting liquid, film-making conditions, gel bath temperature and composition, and pore-forming agent all affect the performance of the film, which is mainly reflected in the mass transfer rate. The pore-forming agent affects the phase separation thermodynamics and mass transfer kinetics of the casting liquid film system, thus affecting the film forming process and changing the film structure.
3) PVP pore-forming mechanism
When PVP is a pore-forming agent, it will be enriched on the surface of the membrane. When the surface of the membrane is in contact with water, PVP will dissolve in water, forming a channel for non-solvent to enter the interior of the membrane, and these points constitute the growth point of the finger hole, which will grow to the parent membrane to form the finger hole in the subsequent process. Finally, the polymer is concentrated and the polymer dilute phase is eluted (PVP).
4) Add scale
The proportion of PVP added is generally 2-5wt% (the range is not fixed, according to the specific film conditions). The increase of the addition amount will increase the porosity of the film, but reduce the strength and hydrophobicity of the film, which will affect the performance of the film.
Application of PVP photoresist to color kinescope
The black base (black matrix) and water-soluble adhesive of color picture tube are the key materials for the production of color picture tube. The substitution of PVA of chromate by aromatic compounds azide, PVP and PAM mixture is an important development of CPT photosensitive adhesive. PVP plays a great role in improving the photosensitive properties of the photosensitive adhesives, bond properties and levelling. Many large color tube factories use nitrogen-containing PVP stacks as an important part of water-soluble photosensitive adhesives at home and abroad. Since photosensitive adhesives and images show the need for more stringent (less than 0.01mm on the black and white stripe interface inequalities, it requires more photosensitive adhesives for PVPK90 quality, especially for molecular weight, viscosity and impurities than general industrial product specifications. In order to ensure the stability of the quality of the production of color picture tubes, the polymerization system and polymerization process of PVPK90 should be devoted to research and adjustment.
The photosensitive resist can also be used for circuit boards, printed circuit boards and other occasions, in addition to CPT and other occasions.
In addition to water-soluble photosensitive adhesives, PVP is also used in photosensitive materials for CPT shadow mask coatings, conductive coatings and fluorescent screens. In these CPT materials, PVP is mainly used as a dispersant and binder for the active ingredient.

Other new material applications in PVP:
PVP can be used in various functions of membrane materials in order to improve membrane selectivity. For example, hemodialysis membranes are made by adding 1-4% PVP in cellulose acetate, only via inulin but not via plasma. Increasing the content of PVP in hydroxypropyl cellulose can increase the water vapor transfer rate. The membranes made of cellulose acetate phthalate and PVP can be used as reverse osmosis membranes to filter organic solvents. Reverse osmosis membrane desalination of seawater can also be improved with PVP to increase its transfer rate. In the process of ultrafiltration, nanofiltration membrane, PVP of various molecular weights can also be prepared for a variety of different polymer materials has been widely used as a pore-making agent, which has a variety of different separation accuracy and different adaptive properties of membrane separation materials can be obtained, who is widely used in seawater desalination, water treatment, concentration and purification products. At present, the global PVP produced by membrane materials used everywhere is about 2000 tons/year, accounting for about 4% of PVP consumption.
PVP can be used in photovoltaic cells or solar cells to stabilize photooxidation/reduction dyes, and can also be used as a solid electrolyte and a binder for the ion electrodes of aluminum electrolytic capacitors in flat glass. The PVP and Cd2O3 can be used as battery electrodes and pressurized mixtures under heating conditions. 75-98% Ni powder and 2-2.5% PVP can be made from nickel-cadmium to support porous and nickel-iron alkaline battery sintered electrodes at 1700℃ for 10 minutes. In addition, it can be the battery electrode to solve magnesium powder in stainless steel fiberboard with PVP. In these cases, PVP is used as a binder and dispersant for metal powders.
PVP can be used in diazo and silver halide emulsions, etch coatings and glues for printing plates to form photocuring water-soluble colloids, which then improve covering power, density, contrast and colloidal speed. In metalophotography, the use of PVP eliminates deep etching and also ensures uniform viscosity, stable temperature, and firm attachment in non-imaging areas. PVP is a very effective protective colloid for silver halide emulsions. PVP can also develop silver colloids to remove the rust of dichromate and can be used as processing AIDS.
Attention and research, the excellent performance of PVP has also received much attention and research on drag reduction coatings, optical fiber, laser disc and other new technologies.
NVP and the copolymer (b) of methylol methacrylate as an ester or glycol ester, and later the graft polymer on PVP, can make highly absorbent soft contact lenses, whose water absorption rate can be up to 90%, with good water permeability, air permeability and mechanical strength.
The PVP and the active metal complexes in the study used as hydrogenation catalysts are captured by everyone’s eyes, for example, palladium PVP complexes using silica as a carrier at room temperature and atmospheric pressure can catalyze the hydrogenation reduction reaction of aromatic nitrocompounds in which their catalytic activity is greater than that of conventional catalysts. The hydrogenation rate of nitrobenzene and dinitrobenzene reached 100%. The appropriate amount of acetic acid added to the system can significantly improve the activity of the catalyst, and the recovery and use hardly reduce the catalytic activity.
In short, in recent decades, the application of PVP in the high-tech field has emerged endlessly, is too numerous to enumerate, involving tens of thousands of patents, but does not deviate from PVP applications. Any new application is related to the excellent performance of PVP, and the most popular one is still water-soluble, membrane, binder, complexing, protective colloid and low toxicity.
The application of PVP in textile printing and dyeing industry
PVP has been widely used in textile printing and dyeing industry because of its complexing ability and colloid protection.
Application in textile industry
PVP has a strong affinity with general organic dyes, especially with direct, reduction, vulcanization, dispersion and other dyes. This is mainly caused by the binding force between the lactam structure in PVP molecules and the organic functional groups in dyes, such as hydroxyl, amino, carboxyl groups. This force often exceeds the binding force of dye and fiber under certain conditions, so PVP is called “liquid fiber”. This property of PVP can improve the dyeability of many hydrophobic synthetic fibers. PVP(or its copolymer) is introduced into synthetic fibers by grafting copolymerization, surface grafting, mixing with synthetic resin, wet spinning fiber impregnation, coating, etc., so that synthetic fibers can be dyed uniformly and the dyeing depth can be improved. For example, 5%-10% of PVPK30 is added to the spinning stock solution of polyacrylonitrile or its copolymer for mixing, and the dyeing depth of the fiber for the following dyes is increased as follows:
CellitonFastYellowGGLL100%
Cellitonfast PinkrF 82%
Celltionfastblueffrs 47%
For polypropylene fibers that are difficult to dye, such as the copolymer of 7.5% ~ 10% ethylene-vinylpyrrolidone added to the resin (containing 75% ~ 90% ethylene) for spinning, the fiber dyeing depth can be increased by nearly ten times for acid dyes and 3 ~ 7 times for dispersive dyes. Viscose, polyamide, polyvinyl chloride and other fibers have the same dyeing effect.
In addition to improving the dyeability of synthetic fibers, PVP can also improve other properties of synthetic fibers. For example, the graft copolymer of PVP and nylon 66 can not only be dyed dark with acidic direct reduction dyes, but also improve its hygroscopic property, wrinkle resistance, shape, easy washable property, strength and sun resistance after bleaching. Another example is the use of 10% PVP mixed viscose fiber, its moisture absorption from 3ml/g, increased to 5 ~ 6ml/g. For example, the copolymer fiber of acrylonitrile and vinyl chloride will produce permeability and loss of light when it meets water or water steam under heat conditions. After adding 3 ~ 5% PVP, the fiber does not have the above phenomenon.

Application in printing and dyeing industry
(1) Because PVP has a strong ability to combine with many kinds of dyes, it was used as a stripping agent, bleach, subtractive agent in the 1950s. More recently, it has been proposed to incorporate maleic anhydride-styrene copolymers into PVP bleach formulations to reduce the cost of bleaching fabrics.
In some special occasions, PVP can be used as levelling agent. For example, 1% PVP can make nylon 6, nylon 66 blended fiber fabrics dyed with acid dyes or metal complex dyes to obtain the best color difference. 2% PVP(wt) can be used as a leveller for modified polyester fiber dyeing with cationic dyes. The dyed fabric not only has uniform color, but also increases the sun fastness from the original two levels to eight levels, and its antistatic property is also increased (the specific impedance is increased from 1.1×106Ω-cm to 1012Ω-cm). When PVP is used as levelling agent, it can be dyed by one-bath method with uniform color and good color fastness.
The ability of PVP to combine with different dyes is different. Using this property, PVP can be used as anti-dye agent in anti-dye printing of animal fiber, polyamide fiber and polypropylene fiber. Adding 3% PVP to the coloring paste can effectively prevent the ground color dyeing (ground color with metal complex dye or disperse dye), and get a bright pattern and clear outline of the printed fabric.
When the ratio of PVP to the metal complex dye is increased (at least 1:2), the marking color – temporary printing dye can be made. After dyeing wool, acrylic, nylon, polyester, viscose fibers with this dye, its color is easy to wash off with water, still leaving white fibers.
Most water-soluble polymer compounds have colloid protection and solubilization, but PVP is particularly excellent in this respect, so it can be used as a structural levelling agent for high temperature dyeing of disperse dyes to improve the stability and dyeing speed of disperse dyes. This disperse dye is prepared by spray drying of PVP and dye together in solvent. The dye and PVP are in solid solution state with particle size < 0.1μ.
Dispersible dyes in solvent dyeing because the dyes are insoluble in solvents, usually need to use a lot of surfactants, solvent recovery is large, dyeing rate, color fastness is low. If PVP(often its derivatives) is used as a dispersant for dye processing, a stable storage disperse dye can be obtained. The solvent dyeing of polyester fiber with this dye can obtain uniform dyed fabrics that are resistant to moisture, wear, heat and light. 1% ~ 3% PVP can prevent thixotropy and degradation of VAT dyes and disperse dyes during storage, and still maintain the fluidity of dye paste after a few weeks. Adding < 3% PVP(measured by solid content) to the hydroxymethyl anti-wrinkle and anti-shrinkage finishing agent can improve the storage stability of such additives. After several months of storage, the remade aqueous solution will not precipitate after a week.
The transfer dyeing and finishing process has the advantages of fast speed, less amount of auxiliaries and good processing quality. The key is to need a kind of fiber affinity, good solvent compatibility, good film formation, suitable for coating paste; It is also required to have dispersion, stability and a certain cohesiveness for dyes and finishing AIDS; Easy preparation; Soluble in water, easy to wash off after dyeing and finishing. Because PVP meets the above requirements, PVP has a wide range of adaptability and good results in transfer dyeing, bleaching, cleaning, finishing (anti-wrinkle, waterproof, antistatic, Antisnag, etc.).
Generally, in fabric finishing, cationic finishing AIDS and anionic fluorescent whitening agents are incompatible and cannot be processed in the same bath. If 0.1 ~ 2% PVP is added to the bath, the fabric can be processed and finished with softener or antistatic agent, resin finishing agent and fluorescent whitening agent at the same time in one bath. The whiteness, fluorescence, softness, electrostatic charge and strength of the treated fabric all reach or exceed the performance index.
(2) Due to the presence of lactam structure in PVP molecules, there is a strong binding force between hydroxyl, amino, carboxylic groups, and dyes often contain these functional groups, so PVP and general organic dyes have a strong affinity, and sometimes this affinity even exceeds the binding force of dyes and fibers, so PVP is known as “liquid fiber”. Using this property of PVP can increase the affinity between some hydrophobic fibers and dyes, and then improve the dyeability of such fibers. For example, in the synthetic fiber process, an appropriate amount of PVP is mixed into it, so that the synthetic fiber can be evenly dyed, and the coloring power and dyeing depth are improved. When about 7.5% NVP/ styrene copolymer is added, the dyeing depth of the fiber for acid dyes can be increased by about 10 times, and that for dispersive dyes can be increased by about 5 times. In the process of mixing PVP, it can be evenly distributed in the fiber, which can greatly reduce the color difference of the dyed fabric and improve the adhesion of the dye on the fabric. The textile dyes with uniform color, light resistance and heat resistance are obtained.
In addition to improving the dyeability of some fibers, PVP can also improve its hygeability, sun protection and other properties, greatly improve the quality and grade of synthetic fibers, such as polyamide fiber, polyester fiber and other synthetic fibers with high strength, high fineness, friction resistance, thermal plasticity and good luster and bright dyeing and popular, but hygeability is worse than natural fibers. As a result, it is often used as clothing to attach a layer of water vapor from the air on the surface of the clothing and affect the comfort of wearing, especially in the summer hot and humid weather, poor moisture absorption clothing is easy to be soaked by sweat or high humidity air and close to the skin, and even irritating to the skin. One way to solve this problem is to add 4%-8% PVP to melted polyamide before spinning, and then melt spinning in a low-oxygen environment. The added PVPK value is between 30 and 70, in which the residual monomer content needs to be less than 0.1%. In this way, the synthetic fibers such as polyamide fiber and polyester fiber have high moisture absorption, washing resistance and thermal plasticity, and as mentioned above, the addition of PVP can also improve some dyeing properties, and control the spinning speed can obtain fibers of different fineness. It is worth mentioning that if the added PVPK value is less than 30, due to the poor complexation ability of low molecular weight PVP and polyamide, there will be some PVP dissolved in water in the water treatment process and not get high hygroscopic fiber. On the other hand, if the molecular weight of PVP is greater than 70, the viscosity of the melting system increases when spinning, making spinning difficult and affecting the production efficiency, and the molecular weight of PVP is too large, the obtained fiber hardness is too large, and can not meet the requirements of synthetic fiber softness and comfort. The moisture absorption rate of polyester fiber improved by PVP-K60 can reach up to 20% of the weight of the fiber itself.

The binding ability of PVP with different dyes is different. Using this property, PVP can be used as local anti-dye agent when printing polyamide fiber and polypropylene fiber, and the printed fabric with bright patterns and clear contours can be obtained. In the production process of printed fabric, the fabric after printing, but also after washing desizing, in order to wash the unfixed dye and paste and other printing and dyeing auxilaries, to get printed fabric products, in order to achieve the purpose of desizing without staining pattern, to ensure the quality of products, the choice of cleaning agent is very important, research shows that, The cleaning agent used in printing and dyeing industry with PVP and sodium aluminate silicate as the main components has significantly higher cleaning capacity than the cleaning agent without PVP, and can prevent the transfer of color or white dirt in the cleaning process.
The application of PVP in materials
Membrane separation is a very important method for separation in recent years, and the performance of separation membranes such as Brominated polyphenyl ether membranes (BPPO) is a key factor in the success of this method. BPPO is a thermoplastic polymer with stable physical and chemical properties and excellent film forming performance, which has shown a good application prospect in gas separation. However, it is not ideal in practical application. For example, due to the weak polarity of BPPO membrane, the separation efficiency of alcohol/n-pentane is not ideal. PVP with strong polarity is blended with BPPO to improve the polarity of the membrane material, and the membrane has appropriate flux and selectivity by adjusting the ratio of PVP/BPPO. Studies show that the performance of the hybrid crosslinked membrane with 10% PVP content is very obvious. For 6.4% methanol solution, the flux is 1.775g/m2.h at 30 degrees. The selectivity is increased to 88%.
As an excellent bonding agent, PVP is used as a cement binder in building materials, which can greatly improve the performance of cement, especially increase the compressive and seismic strength of cement. For example, as a Butran cement binder, it contains about 3% PVP (molecular weight 40000), more than 90% sodium naphthalene sulfonate and a small amount of formaldehyde, which significantly improves the strength of cement concrete.
PVP has good adhesion for glass, plastics and metals, is the main component of the manufacture of special purpose hot sol, using it as a binder for glass and plastics, the initial adhesion is strong, high adhesion strength, in the glass fiber reinforced composite material, the hot melt adhesive containing PVP is a better adhesion of glass fiber and other plastics.
In addition, PVP has important uses in conductive materials, various membrane functional materials, and in the field of new materials such as drag reducing materials, optical fiber, laser optic disc, photosolid resin, and photosensitive materials.
The application of PVP in chemical reaction and analytical chemistry
1. Application of PVP in polymerization reaction
The viscosity and colloidal protection function of PVP make it have important applications in polymerization reactions, especially in emulsion polymerization and suspension polymerization, adding a small amount of PVP can play a role in dispersion stability, thickening and particle size control, such as suspension polymerization of methacrylate and polyamine ester. In the emulsion polymerization system of acrylate and vinyl acetate, appropriate amount of PVP-K60 or PVP and styrene copolymer was added to make the reaction system disperse uniformly and stably, and the viscosity, polymer particle size and particle size distribution could be adjusted by adjusting the molecular weight and dosage of PVP, and some properties of the resin could be improved. When ~3% PVPK60 was added to the suspension polymerization of polyurethane, the polymer powder size was uniform, the particle size was between 800~100 microns, and the residual monomer was less than 0.5%. Can be used in coatings, binder, laminate composite materials, made of film, thickness of up to 100 microns, as a coating, coating degree can be as small as 10 microns.
In some emulsion polymerization systems, PVP-K15 or PVP-K30 with lower molecular weight can make the reaction more complete, increase the polymerization rate and improve the mechanical properties of the polymer. For example, when PVP-K15 is added as an emulsifier, the polymerization of methyl methacrylate can be completed within half an hour at 50 degrees, and the resulting polymer elastic temperature range is 120 to 280 degrees, while the polymer elastic temperature range is relatively narrow, 120 to 150 degrees, without PVP. It also shows that the polymer obtained by using PVP as dispersion stabilizer has good thermal stability.
2.PVP can be used in analytical chemistry and catalysts
The aqueous solution of PVP can be divided into liquid-liquid or liquid-solid phases in the presence of different amounts of (NH4) 2SO4. This system is used for the extraction separation of metal ions by organic solvents, and a new extraction system can be obtained. The system has a good extraction effect for some metal ions, such as PVP- (NH4) 2SO4-H2O system containing PVP20%, using arsine azo (III) as the extraction agent to react in the solution containing Zr (IV), La (III) ions to form a complex, under certain conditions, The chelate of Zr (IV) and arsine azo has a high extraction rate in the PVP phase, while the extraction rate of La (III) is very low, so as to achieve the purpose of separating Zr (IV) and La (III). In addition, PVP and some metals themselves have good complexation, such as PVP and a trace of Cd can be complexed to produce PVP-CD. This property can be used to successfully detect trace amounts of cadmium. In addition, related studies have reported that for methanol gas phase carbonylation, the activity and selectivity of carbon-supported collolawrencium catalyst (PVP-RH /C) is much higher than that of simple carbon-supported rhodium catalyst, because the lawrencium collolawrencium catalyst formed with PVP has narrow particle size distribution, high dispersion and larger specific surface area. The selectivity of the reaction was improved as well as the catalytic activity.
The application of PVP in organic pigments
The organic pigment particles obtained by chemical synthesis method have a large specific surface range, the specific surface is 8~100m2/g, and the usual mechanical treatment method can only make the pigment particle size reach 70~100 microns, and can not be directly used. Therefore, people use surface treatment technology to change some properties of the pigment, such as dispersion, thermal stability, solubility resistance, chemical inertness and optical solid properties. In fact, the surface treatment of pigments is to use some method to prevent the particles from growing before the pigments gather into large particles, and the best way is to protect the pigment particles and give them the required performance.
PVP has good film forming properties, soluble in water and insoluble in some organic solvents, most of the substances used in pigment solvents make organic solvents, and PVP has better film forming properties with the increase of molecular weight. When the solubility of organic solvents is poor, PVP (molecular weight greater than 30000) is used to treat pigment particles. Due to the affinity between PVP and pigment molecules, a transparent film is formed on the surface of the pigment. The formed film is not soluble in organic solvents, so it is not easy to be destroyed. And it can improve the luster and dispersion of the pigment, cut off the contact between the organic pigment and the external environment, and indirectly give the chemical stability and thermal stability of the organic pigment, avoid the chemical reaction caused by some substances or photothermal with the external environment, and improve the photosolid properties of the pigment. PVP for the surface treatment of organic pigments is generally PVP-K30, PVP-K90 or PVPVA64. The particle size of organic pigment after PVP treatment is between 0.1 and 10 microns. The amount of PVP is generally 5~10% of the quality of organic pigments. The main pigments available for PVP surface treatment are: protective and decorative coatings, such as varnish, paint, etc.; Aqueous dispersion system; Printing, ink, fabric coloring and plastic coloring, latex, etc.
The excellent dispersion performance of PVP can also be used for the dispersion of carbon black, phthalocyanine pigments, titanium dioxide and other pigments.

The application of PVP in coating
In emulsion coatings and water-soluble resin coatings, the coloring effect is reduced due to the poor dispersibility of pigments and the condensation precipitation during storage, and there are bad phenomena such as floating color and poor luster. The addition of medium molecular weight PVP (PVPK30) can improve the coloring power, eliminate the floating color phenomenon, disperse and stabilize the pigment composition, improve the luster, and avoid the flocculation precipitation of the pigment. The viscosity of the emulsion coating with styrene and methacrylate as the main body is often very low, resulting in poor water resistance of the coating, the fluidity of the coating is too large, the thickness of the film is not easy to control, and the hardness is not enough, and it will fall off, so it needs to be thickened and viscosified. The viscosity of this kind of emulsion can be increased by more than 10 times by adding an appropriate amount of PVP into the emulsion, and a stable synthetic resin solution with high viscosity can be obtained. The coating prepared with PVP adhesive coating emulsion has the advantages of non-hanging, good water resistance, hard film, no shedding, stain resistance and so on.
The paper transparent coating containing PVP makes the printing ink dry quickly on it, has good ink absorption, insoluble in water, and has good coagulability and diffusivity. In addition, PVP has important uses in other coatings, such as conductive coatings, electrode coatings, and anti-leakage coatings. For example, the insulating layer outside the conductive material, after repeated sudden heat, sudden cooling, sun and rain, will age or break, or leak electricity because of water seepage. A layer of PVP film (PVPK90) is formed on the outside of the insulation layer. On the one hand, PVP film is transparent and does not affect the natural color of the insulation layer. On the other hand, PVP film is bonded with the insulation layer to isolate the insulation layer from external light, heat, rain, etc., avoiding the leakage phenomenon caused by water seepage and cracking, and reducing the aging speed caused by light and heat. The service life of the wire is extended, and the hardness of the wire is appropriately increased.
PVP in other applications
PVP film forming property can be used for corrosion prevention and corrosion inhibition of iron, aluminum and other equipment. Due to its multi-center adsorption function, PVP has a good inhibition effect on acid corrosion of iron and aluminum. The anticorrosion function of PVP increases with the increase of PVP concentration and the decrease of molecular weight.
PVP can also be used as a silver halide emulsion dispersion stabilizer, which can reduce viscosity and enhance covering power. Adding a small amount of PVP to the developer can eliminate the appearance of color spots. PVP as the adhesive composition of pressure sensitive adhesive can make the pressure sensitive adhesive have good initial viscosity, good stripping property, and can be used repeatedly. In the oil production industry, PVP is used as an additive to mud, which can increase mud viscosity and improve curing speed.
The application of PVP in agriculture has also been increasingly paid attention to, for example, PVP solution coated on seeds, can reduce the damage during soaking, with obvious biological protection function. The organic solvent can be gelatinized by PVP and mixed with explosive liquid propellant to form solid or paste, which is easy to transport and store.
With the development of science and technology, in recent years, PVP with excellent performance has been found to have important uses in many new fields, and the gradual improvement of PVP polymer properties has also shown its strong vitality. With the development of our national economy and the continuous progress of science and technology, we should and will make greater progress in the field of PVP production and application research and development.
PVP in other areas
PVP can be used as a slurry additive in the oil production industry to increase viscosity and cure time and reduce the water loss rate. It is a very stable acid gel and is used in acid cracking operations. Because it is less sensitive to salt concentrations, PVP can be used in polymer flooding tools at high salt concentrations. In surfactant flooding areas, such as injected PVP solution before the injection of surfactants, PVP can greatly reduce the loss of surfactants.
Regardless of its raw material distance for papermaking, PVP has been applied in various types of papermaking technologies. Its wide range of use includes improved wet strength, improved solubility of dyes and pigment dispersions, and PVP is an excellent additive for deinking, runout, coloring.As an anti-caking agent and flow aid for coatings, PVP makes the final paper product smooth to prevent oil and make printing performance good. For those occasions who still want to get the paper coated after getting wet, PVP can prevent the paper from curling and wrinkling.
PVP is the main type of polymer quenching agent. Polymer quenching agent can improve the characteristics of water cooling, its main advantages are: (1) to reduce the risk of fire: the use of PVP as hardener can avoid fire easily caused by oil bath; (2) The operation can be flexible: the concentration, temperature and stirring of the solution by others who control PVP can be controlled accordingly by a series of cooling rates, so that they are made of a series of materials to complete the hardening better; (3) to reduce hardening costs: commercially sold PVP is usually a higher concentration solution, and the price is higher than oil quenching, but as a result of quenching only requires a very low PVP solution concentration, the actual price is lower than oil quenching; (4) Maintain a clean environment: Because the ordinary heat treatment workshop has oil residue and silt, toxic gases they release pollute the environment. But after using PVP as hardener, they released water vapor without contamination. In the United States, the Environmental Protection Council has banned the use of oil quenchers in many areas; (5) to reduce operating costs: due to the reduction of fire hazards, in a certain sense, it is also to reduce costs. In addition, PVP quenching solution is almost twice as hot as oil, so the temperature rise of PVP hardener is half of the oil by exactly the same volume, and then it can improve quenching production.
In 1975, the United States Meszaros first proposed that PVP aqueous solution can be used as hardener, and its best average molecular weight is 160000 (that is, PVPK-60), the same, its best concentration is 10%. From now on, PVP products as hardeners have been applied in the United States and have been promoted around the world. The global consumption of PVP for metal heat treatment is about 4 million tons/year, accounting for about 10% of the total consumption of PVP.
Because PVP is not phytotoxic, it can be used in plant protection sprays, fertilizers, and wetting pesticides. PVP membranes can protect flowering leaves from wilt when they are transplanted, reducing wind and frost damage. PVP can reduce seed soaking damage and protect its physiological function. PVP iodine is an effective fungicide and insecticide for factories. Especially in aquaculture, it can give aquaculture water, aquaculture equipment disinfection and disinfection, greatly reduce the disease caused by bacteria fish, bullfrogs, shrimp and other aquatic products things; In dairy cows, it can be used as a disinfectant for cow udders, milking devices, and greatly reduce the occurrence of bovine mastitis.
Because of the excellent characteristics of PVP, over the decades, we have found many new applications of PVP; Using new polymerization techniques and copolymerization methods, the properties of NVP polymers can be further improved, thus opening up some new application areas.