Water-soluble polymer polyvinylpyrrolidone

PROPERTIES AND USE IN ANALYSIS OF WATER-SOLUBLE POLYMER - POLYVINYLPYRROLIDONE... 

Polyvinylpyrrolidone (PVP) is water-soluble polymer, whieh is widely used in various industries and agrieulture beeause of high inelination to the eomplex formation and eapaeity to stabilization of different systems. 

Other investigators have also studied similar synthetic polymers.11-17 In our experience no water-soluble polymer binds small molecules with an avidity comparable to serum albumin. A comparison of the latter with two of the best-binding polymers18 is shown in Fig. 1. Neither polymer binds as strongly as serum albumin. Despite its large cationic charge and many apolar (—CH2—CH2—CH2—CH2—) side chains, polylysine shows very weak affinity for anions. Polyvinylpyrrolidone is more effective but not impressive. 

These polymers have high intrinsic viscosities [e.g., about 22 (ml/g), for polyvinylpyrrolidone], which indicates that the macromolecules are swollen and extended in water. In contrast, serum albumin, with an intrinsic viscosity near 4 (ml/g), must be relatively compact. Promising approaches might be, therefore, to obtain a relatively compact conformation with a water-soluble polymer by introducing cross-linkages or by using a highly branched matrix. The latter has proved to be particularly fruitful. 

In certain water-soluble polymers such as polyvinylpyrrolidone, the minimum dose required for gel formation shows a curious dependence on concentration. As this is reduced to about 1%, the gelation dose decreases in spite of the fact that the polymer molecules are further apart. This is ascribed to the higher contribution made to polymer radi-... 

Tachibana T, Nakamura A. A method for preparing an aqueous colloidal dispersion of organic materials by using water-soluble polymers dispersion of beta-carotene by polyvinylpyrrolidone. Kolloid-Z Polym 1965 203 130-133. 

Generally, the barrier or rate-controlling films are more permeable to water than the carrier films. The materials used for this purpose consisted of a base, film forming water-soluble polymer in combination with at least one hydrophilic component such as hydroxypropyl methylcellulose or polyvinylpyrrolidone. The polymers used were the same as those for the carrier films. Some recent developments are discussed herein. 

Dobry and Boyer-Kawenoki (1948) showed that phase separation occurs in mixed solutions of many water-soluble polymers such as gelatin, serum albumin, gum arabic, glycogen, polyvinyl alcohol, polyvinylpyrrolidone, methylcellulose, polyacrylic acid, and so on. They have shown that immiscibility or limited co-solubility is typical of all polymers. The theory of the thermodynamic incompatibility of polymers was devel-... 

Some water-soluble polymers like polyvinylpyrrolidone 16 63-6S) and poly (methacrylic add) 17 (66) are known to bind many organic molecules in aqueous s3rstems. This peculiar behavior has been explained based on the hydrophobic nature... 

The Interaction of water soluble polymers with microemulsions and with surfactants will, when the components are sufficiently concentrated, often result in a phase separation or change in the phase boundaries of the mixture as a function of external variables, such as temperature or salinity. In order to arrive at a better understanding of this technologically Important phenomenon, a series of experimental studies was carried out using a variety of water soluble polymers in conjunction with model mlcroemulslon systems. The polymers used Included polyethylene oxide, polyvinylpyrrolidone, dextran, xanthan, polyacrylamide, and hydrolyzed... 

Suzuki and Sunada " also prepared solid dispersions of nifedipine with other combined carriers using a fusion (melt) method. The combined carriers were nicotinamide and four different water-soluble polymers hydroypropyl methylcellulose (HPMC), polyvinylpyrrolidone (PVP), partially hydrolyzed polyvinyl alcohol (PVA), and pullulan. HPMC, PVP, and PVA dissolved in the melt of nicotinamide and were effective in the amorphous formation of nifedipine in solid dispersions. In dissolution studies, the drug concentration... 

An attempt to improve the defect has been made by the addition of HPC or polyvinylpyrrolidone (PVP) which removed the defect of diazepam (Fig. 14.12). Likewise, Loftsson et al. have reported the enhancement of oral drug bioavailability as a result of the combined action of CyD complexation and water-soluble polymers such as HPC or PVP. The enhancement is caused by an increase in the apparent stability constant of the drug/CyD complexes via the formation of ternary drug/CyD/polymer complexes [83]. 

Polyvinylpyrrolidone (PVP), commonly called polyvidone or povidone, is a water-soluble polymer made from the monomer iV-vinylpyrrolidone [87,88]. Dry PVP is a light flaky hygroscopic powder and readily absorbs up to 40%... 

Polyvinylpyrrolidone (PVP) was widely used during World War II and the Korean War as a plasma expander. Subsequently, PVP was extensively studied and it was found that this synthetic water-soluble polymer cannot be broken down in the body. Thus it is used today only to a limited extent. Since this substance illustrates the problems encountered in the use of completely synthetic colloids as plasma expanders, a short survey, mainly of historical interest, will be presented. 

Granulation requires the use of binders to form the granules, and make them harder and less likely to fracture. Water-soluble polymers, such as polyvinylpyrrolidone and starches or other polysaccharides, are commonly used to increase the adhesion between particles. Water-soluble binders are used to produce rapid and complete breakup back to the primary particle size. Some surfactants and polymers can also act as binders, especially for mechanical granulation techniques. 

Disintegrants encourage the rapid breakup of the granules back to their primary particle size. The compounds used are often highly water-soluble polymers and inorganic salts. Disintegrants generally absorb water quickly, swell, and break the particles apart. Cross-linked polyvinylpyrrolidones... 

Similar conclusions were reached in our laboratory when evaluating water-soluble polymers for a more hostile application in seawater at 121 C (250 F). In our tests, only polyvinylpyrrolidone... 

As stated earlier, an extensive laboratory review of many available commercial water-soluble polymers and selected experimental water-soluble polymers was conducted. A summary of the results is given in Table I. As shown, only polyvinylpyrrolidone survived the 121 (250 ) test in synthetic seawater more than a few days. Polyvinylpyrrolidone is not however an efficent viscosifier. Combined with its high adsorption characteristics in reservoir rock (polyvinylpyrrolidone has been used in selected cases as a sacrifical agent) and high price, polyvinylpyrrolidone is regarded as unsuitable for use in EOR. 

Because of their proclivity to associate in solution, it is to be expected that surfactants and polymers can influence each other s solubility. There is abundant evidence of the ability of a surfactant to increase the range of solubility of polymers in water (see the next section). Less well known is the ability of a water-soluble polymer to increase the solubility range of a surfactant Schwuger and Lange (103), for example, reported that polyvinylpyrrolidone can reduce the Krafft point of sodium hexadecyl sulfate by close to 10°C—an effect evidently linked to a lowering of the monomer concentration required for aggregation in the presence of this polymer. 

Now it is known that a number of classes of water-soluble polymers interact with and are mutually coagulated by polysilicic acids and coiloidal silicas. These include polyethers (polyethylene oxide.s, methyl cellulose), polyamine salts (polyethylene iminc), poIyalcohoLs (polyvinyl alcohol), polyvinylpyrrolidone, and proteins (gelatin, albumin). 

In 2009, an estimated four billion metric tons of natural, semisynthetic, and synthetic water-soluble polymers were consumed globally for use in the production of food, clean water, energy, for personal care, pharmaceutical, and industrial applications [1], Synthetic water-soluble polymers synthesized by free radical addition polymerization methods account for half of this volume. They include polyacrylamides, polyacrylates, polydiaUyldimethylammonium chloride (polyDAD-MAC), polyvinyl alcohol, and polyvinylpyrrolidones. Depending on the target applications, these polymers can have different molecular weight, charge, and architecture. 

Even though this technique has been mostly used with water-soluble polymers, such as PEO, polyvinyl ether (PVE), polyvinylpyrrolidone (PVP), and poly(acrylic acid) (PAA) [134-141], intercalation from nonaqueous solutions has also been reported [142-145]. For example, high-density polyethylene (HDPE)-based nanocomposites have been prepared by dissolving HDPE in a mixture of xylene and benzonitrile with dispersed organomodified layered silicates (OMLSs). The nanocomposite was then recovered by precipitation from tetrahydrofuran (THE) [143], Polystyrene (PS)/OMLS-exfoliated nanocomposites have also been prepared by the solution intercalation technique, by mixing pure PS and organophilic clay with adsorbed cetyl pyrid-ium chloride [146]. Similarly, several studies have focused on the preparation of polylactide (PLA)-layered silicate nanocomposites using intercalation from solution. 

There are water-soluble polymers such as PVA, PAA, polyvinylpyrrolidone (PVP), polyacrylamide (PAM), polyethylene glycol (PEG), and polyethyleneimine (PEI). These polymers can be directly electrospun using water as solvent, which avoid the treatment of toxic organic solvent vapor. On the other hand, these water-soluble polymer nanoflbers are easy to swelling or collapse upon moisture thus, the obtained nanoflbers should be kept in special dry environment to prevent the fiber structure from destroying. 

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