Polyacrylic acids

Polyacrylic acid (PAA] is a biodegradable water-soluble polymer with a wide range of medicinal applications and is considered pharmaceutically safe. They are used for oral and mucosal contact applications in the form of controlled release tablets, oral suspensions, and bioadhesives. The unique property of PAA is that it exists as a liquid at pH 5 and as a gel at pH 7. Permeation of cations into the gelled polymer converts the gel back to a liquid. It is an ideal polymer used for ocular delivery of ribozymes to the corneal epithelium as a drug delivery vehicle. 

Polyacrylic acid can be prepared by adopting acrylic acid as raw material. The structure of polyacrylic acid is as follows  

PolyacryUc acid is a typical anionic flocculant which is able to flocculate the Ca, Mg, and Ba minerals under alkaline conditions. 

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Water-soluble polymers and polyelectrolytes (e.g., polyethylene glycol, polyethylene imine polyacrylic acid) have been used success-hilly in protein precipitations, and there has been some success in affinity precipitations wherein appropriate ligands attached to polymers can couple with the target proteins to enhance their aggregation. Protein precipitation can also be achieved using pH adjustment, since proteins generally exhibit their lowest solubility at their isoelectric point. Temperature variations at constant salt concentration allow for frac tional precipitation of proteins. 

Leadley and Watts also investigated the interaction of polyacrylic acid (PAA) with oxidized metal substrates [26]. Through careful curve fitting of the C(ls) spectra, three specific types of interaction between PAA and the oxidized metal... 

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. 

Individual components in the formulation of the aqueous phase all contribute to the successful production of a GPC/SEC gel. The stabilizer acts as a protective coating to prevent the agglomeration of the monomer droplets. Polyvinyl alcohol, gelatin, polyacrylic acids, methylcellulose, and hydroxypro-... 

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

The GBR resin works well for nonionic and certain ionic polymers such as various native and derivatized starches, including sodium carboxymethylcel-lulose, methylcellulose, dextrans, carrageenans, hydroxypropyl methylcellu-lose, cellulose sulfate, and pullulans. GBR columns can be used in virtually any solvent or mixture of solvents from hexane to 1 M NaOH as long as they are miscible. Using sulfonated PDVB gels, mixtures of methanol and 0.1 M Na acetate will run many polar ionic-type polymers such as poly-2-acrylamido-2-methyl-l-propanesulfonic acid, polystyrene sulfonic acids, and poly aniline/ polystyrene sulfonic acid. Sulfonated columns can also be used with water glacial acetic acid mixtures, typically 90/10 (v/v). Polyacrylic acids run well on sulfonated gels in 0.2 M NaAc, pH 7.75. 

Polyacrylic acid (pAA) homopolymers and related copolymers have become a commercially important class of water-soluble polymers. Acrylic acid polymers can range in molecular mass from less than 1000 Da to greater than 1,000,000 Da. A representative set of analysis conditions is... 

J.-L. Liao, C-M. Zeng, S. Hjeiten and J. Pawliszyn, Solid phase micro exti action of biopolymers, exemplified with adsorption of basic proteins onto a fiber coated with polyacrylic acid , ]. Microcolumn Sep. 8 1-4. (1996)... 

ACPA azobis(4-cyanopentanoic acid) AIBN azobis isobutyronitrile) BPO benzoyl peroxide DVB divinyl benzene, EGA 2-ethylcyano-acrylate HPC hydroxypropyl cellulose MMA methyl methacrylate PAAc polyacrylic acid PEI polyethyleneimine, PEO/PPO polyethylene oxide/polypyropylene oxide copolymer PVME polyvinylmethylether PVP polyvinylpyrrolidone K-30 DMSO dimethylsulfoxide PGA polyglutaraldehyde CMS chloromethylstyrene PMMA-g-OSA polymethylmethacrylate grafted oligostearic acid. 

We also studied the effect of initiator on the dispersion polymerization of styrene in alcohol-water media by using a shaking reactor system [89]. We used AIBN and polyacrylic acid as the initiator and the stabilizer, respectively. Three different homogenous dispersion media including 90% alcohol and 10% water (by volume) were prepared by using isopropanol, 1-butanol, and 2-... 

We have also examined the effect of stabilizer (i.e., polyacrylic acid) on the dispersion polymerization of styrene (20 ml) initiated with AIBN (0.14 g) in an isopropanol (180 ml)-water (20 ml) medium [93]. The polymerizations were carried out at 75 C for 24 h, with 150 rpm stirring rate by changing the stabilizer concentration between 0.5-2.0 g/dL (dispersion medium). The electron micrographs of the final particles and the variation of the monomer conversion with the polymerization time at different stabilizer concentrations are given in Fig. 12. The average particle size decreased and the polymerization rate increased by the increasing PAAc concentra-... 

The soapless seeded emulsion copolymerization method was used for producing uniform microspheres prepared by the copolymerization of styrene with polar, functional monomers [115-117]. In this series, polysty-rene-polymethacrylic acid (PS/PMAAc), poly sty rene-polymethylmethacrylate-polymethacrylic acid (PS/ PMMA/PMAAc), polystyrene-polyhydroxyethylmeth-acrylate (PS/PHEMA), and polystyrene-polyacrylic acid (PS/PAAc) uniform copolymer microspheres were synthesized by applying a multistage soapless emulsion polymerization process. The composition and the average size of the uniform copolymer latices prepared by multistage soapless emulsion copolymerization are given in Table 11. 

Whereas PVA fleeces are used only in primary cells polyamide fleeces compete with polyolefin, preferably polypropylene fleeces. The latter are more stable at higher temperatures and do not contribute to electrolyte carbonation, but they wet only after a pretreatment either by fluorination [131] or by coating and crosslinking with hydrophilic substances (e.g., polyacrylic acid [132]) on the surface of the fiber. 

NOTE PAA = Polyacrylic acid or sodium salt SHMP = Sodium hexametaphosphate SSMA = Sulfonated styrene maleic anhydride... 

A wide range of polyacrylic acids (PAAs), polymethacrylic acids (PMAAs), polyacrylamides (PAMs), their salts and homo-, co-, and terpolymer derivatives are available from a great many manufacturers around the world today. Polyacrylates especially are a backbone of BW chemical formulations and are manufactured with an almost infinite variety of average molecular weights (MWs), MW distributions, activity strengths, and other characteristics. 

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. 

Nanosize particles of polyacrylic acid were synthesized in w/o microemulsions using azobisisobutyronitrile as lipophilic radical initiator, which were considered suitable for encapsulation of peptides and other hydrophilic drugs [195],... 

Lin, TH Phillies, GDI, Prohe Diffusion in Polyacrylic Acid Water—Effect of Polymer Molecular Weight, Journal of Colloid and Interface Science 100, 82, 1984. 

Wall, F. T. Drenan, J. W. (1951). Gelation of polyacrylic acid by divalent ions. Journal of Polymer Science, 7, 83-8. 

Gregor, H. P. Frederick, M. (1957). Titration studies of polyacrylic acid and polymethacrylic acids with alkali metals and quaternary ammonium bases. Journal of Polymer Science, 23, 451-65. 

Gregor, H. P., Luttinger, L. B. Loebl, E. M. (1955b). Metal-polyelectrolyte complexes. IV. Complexes of polyacrylic acid with magnesium, calcium, cobalt and zinc. Journal of Physical Chemistry, 59, 990-1. 

Jacobsen, A. (1962). Configurational effects of binding of magnesium to polyacrylic acids. Journal of Polymer Science, 57, 321-36. 

Wall, F. T. Gill, S. J. (1954). Interaction of cupric ions with polyacrylic acid. Journal of Physical Chemistry, 58, 1128-30. 

Beech, D. R. (1972). A spectroscopic study of the interaction between human tooth enamel and polyacrylic acid (polycarboxylate cement). Archives of Oral Biology, 17, 907-11. 

Crisp, S., Lewis, B. G. Wilson, A. D. (1975). Gelation of polyacrylic acid aqueous solutions and the measurement of viscosity. Journal of Dental Research, 54, 1173-5. 

Foster, J. F. Dovey, E. H. (1974). Surgical cements of improved compressive strength containing stannous fluoride and polyacrylic acid. US Patent 3,856,737. 

Smith, D. C. Cartz, L. (1973). Crystalline interface formed by polyacrylic acid and tooth enamel. Journal of Dental Research, 52, 1155. 

Wilson, A. D. (1974). Alumino-silicate polyacrylic acid and related cements. British Polymer Journal, 6, 165-79. 

Silvey, R. G. Myers, G. E. (1976). Clinical studies of dental cements. VI. A study of zinc phosphate EBA-reinforced zinc oxide eugenol and polyacrylic acid cements as luting agents in fixed prostheses. Journal of Dental Research, 56, 1215-18. 

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