Anion polyacrylate

Anionic Polyacrylic acid (Na) Polyalginic acid (Na) Hyaluronic acid Carrageenan 0.1 M NaNOj... 

A current area of interest is the use of AB cements as devices for the controlled release of biologically active species (Allen et al, 1984). AB cements can be formulated to be degradable and to release bioactive elements when placed in appropriate environments. These elements can be incorporated into the cement matrix as either the cation or the anion cement former. Special copper/cobalt phosphates/selenates have been prepared which, when placed as boluses in the rumens of cattle and sheep, have the ability to decompose and release the essential trace elements copper, cobalt and selenium in a sustained fashion over many months (Chapter 6). Although practical examples are confined to phosphate cements, others are known which are based on a variety of anions polyacrylate (Chapter 5), oxychlorides and oxysulphates (Chapter 7) and a variety of organic chelating anions (Chapter 9). The number of cements available for this purpose is very great. 

For coupling to be selective, the chain to be coupled must be end-capped by mutually reacting groups. For example, a living anionic polyacrylate or polymethacrylate can be directly coupled to any polymer or copolymer end-capped by a suitable electrophile. Fladjichristidis and coworkers coupled living anionic PMMA chains with the living PtBuA anion of PS- Zoc -PtBuA by reaction with l,2-bis(bromomethyl)benzene, with formation of a triblock copolymer . ... 

PERAPRET D and PERAPRET DS are anionic polyacrylate dispersions with low viscosity. They have a solids content of approx. 25% and a pH of 2-3. They are both used to facilitate the removal of soil from textiles, particularly blends of cellulosic and synthetic fibres, under normal conditions of household washing. They are, therefore, applied as additives in soil-release finishing. The treating liquor must, of course, only contain products that do not impair this desired effect. 

PERAPRET HVN is the aqeuous dispersion of an anionic polyacrylate which contains reactive groups. It has a solids content of approx. 40% and a pH of 5-7. 

TEXAPRET A is a highly viscous, aqueous, anionic, polyacrylate-type solution with a solids content of approx. 15% and a neutral reaction. 

Ap-30 is hydrolyzed polyacrylamide with -COOH and -CONH2 groups (30% concentration) P-250 is anionic polyacrylamide Sedomax-F is anionic polyacrylic acid A-150 is cationic polyacrylamide. 

Nystrom R, Hedstrom G, Gustafssrai J, Rosenhohn JB (2004) Mixtures of cationic starch and anionic polyacrylate used for flocculation of calcium carhonate-influcaice of electrolytes. Colloids Surf A 234 85... 

The most widely used pitch control method is the addition of pitch dispersants, which can be either organic, ie, typically anionic polymers such as naphthalene sulfonates, ligninsulfonates, and polyacrylates (33,34), or inorganic, ie, typically clay or talc. The polymers maintain the pitch as a fine dispersion in the pulp, preventing agglomeration and potential deposition on the paper machine or the sheet. When talc, clay, or other adsorbent fillers are added to the furnish, moderate amounts of pitch can adsorb on these materials, producing a nontacky soHd that can be retained in the sheet. 

Ionic repulsion between anionic samples and the resin causes poor resolution. As shown in Fig. 4.17, the addition of only 0.01 M NaNO, results in normal elution and peak shape for an anionic polymer, sodium polyacrylate. 

Anionic hydrophilic Sodium chondroitinsulfate, sodium alginate, carboxymethyj cellulose, sodium polyacrylate, sodium hyaluronate Buffer or salt solution (e.g., 0.1 M NaNO,)... 

FIGURE 4.17 Effect of ionic strength on the elution of anionic polymers. Column TSK-GEL GMPW, two 17 fjLirt, 7.5 mm X 60 cm columns in series. Sample 0.5 ml of 0.05-0.1% of the sodium salt of polyacrylic acid, an anionic polymer. Elution Water 0.01, 0.025, 0.05, or 0.1 M NaNOs in water. Flow rate 0.5 ml/min. Detection Rl. 

Anionic, hydrophilic Sodium polyacrylate, sodium hyaluronate, carboxymethyl cellulose 0.1-0.3 M salt/buffer, pH 7-9... 

Polyacrylics are produced by copolymerizing acrylonitrile with other monomers such as vinyl acetate, vinyl chloride, and acrylamide. Solution polymerization may be used where water is the solvent in the presence of a redox catalyst. Free radical or anionic initiators may also be used. The produced polymer is insoluble in water and precipitates. Precipitation polymerization, whether self nucleation or aggregate nucleation, has been reviewed by Juba. The following equation is for an acrylonitrile polymer initiated by a free radical ... 

Polyacrylates are anionic in character, and those with a MW of approximately 1,500 to 2,000 are useful as calcium carbonate anti-scalents under severe operating conditions. An example is Polacryl A30-43. 

In the same year, Fulda and Tieke [75] reported on Langmuir films of monodisperse, 0.5-pm spherical polymer particles with hydrophobic polystyrene cores and hydrophilic shells containing polyacrylic acid or polyacrylamide. Measurement of ir-A curves and scanning electron microscopy (SEM) were used to determine the structure of the monolayers. In subsequent work, Fulda et al. [76] studied a variety of particles with different hydrophilic shells for their ability to form Langmuir films. Fulda and Tieke [77] investigated the influence of subphase conditions (pH, ionic strength) on monolayer formation of cationic and anionic particles as well as the structure of films made from bidisperse mixtures of anionic latex particles. 

For the characterization of Langmuir films, Fulda and coworkers [75-77] used anionic and cationic core-shell particles prepared by emulsifier-free emulsion polymerization. These particles have several advantages over those used in early publications First, the particles do not contain any stabihzer or emulsifier, which is eventually desorbed upon spreading and disturbs the formation of a particle monolayer at the air-water interface. Second, the preparation is a one-step process leading directly to monodisperse particles 0.2-0.5 jim in diameter. Third, the nature of the shell can be easily varied by using different hydrophilic comonomers. In Table 1, the particles and their characteristic properties are hsted. Most of the studies were carried out using anionic particles with polystyrene as core material and polyacrylic acid in the shell. 

Use anionic polymers such as polyacrylic acids cross-linked with allyl ethers of pentaerythritol or sucrose as thickeners, if a gel structure and pseudoplastic (shear-thinning) properties are desirable. Consider adding colloidal alumina to further increase the viscosity at pH 13 [ 15]. 

The mucoadhesive properties of several classes of hydrogels have been identified, and two types of polymers have attracted special attention. Polyacrylates and their cross-linked modifications represent the anionic type, chitosan and its derivatives the cationic group. In addition, both types of polymers show a number of interesting characteristics beneficial for the administration of a wide range of therapeutics. 

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