Polyacrylic acid products

Commercial product actives content tends to decrease with increase in MW, from 65% possible at 1000 to 25% at 250,000. A strength of 40 to 50% is usual for cooling water polyacrylates and polyacrylic acid products. 

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-... 

The three categories of major ingredients discussed above for the formulation of water-reducing admixtures account for the majority of commercially available products, but there may be limited use of insitol [28], polyacrylamide [29], polyacrylic acids [30] and polyglycerol [31]. 

Properties of composites obtained by template poly condensation of urea and formaldehyde in the presence of poly(acrylic acid) were described by Papisov et al. Products of template polycondensation obtained for 1 1 ratio of template to monomers are typical glasses, but elastic deformation up to 50% at 90°C is quite remarkable. This behavior is quite different from composites polyacrylic acid-urea-formaldehyde polymer obtained by conventional methods. Introduction of polyacrylic acid to the reacting system of urea-formaldehyde, even in a very small quantity (2-5%) leads to fibrilization of the product structure. Materials obtained have a high compressive strength (30-100 kg/cm ). Further polycondensation of the excess of urea and formaldehyde results in fibrillar structure composites. Structure and properties of such composites can be widely varied by changes in initial composition and reaction conditions. 

The molecular weight of the grafted chain of polyacrylic acid, determined by acid hydrolysis, is of the order of 10000. The product differs markedly from the original polyamide in electrochemical properties. As a confirmation of a radical mechanism, radical acceptors prevented the reaction (see Fig. 5). The possibility of a minor and competitive ionic mechanism was also considered. 

A number of polymers exhibit this hydration property. Natural products such as cellulose and starch are or can be made water soluble. Synthetics such as polyvinyl alcohol and polyacrylic acid are also soluble in water. This discussion will be limited to synthetic materials such as polyacrylic acid and its salts, polyvinyl alcohol, polyacrylamide, and polyurethane... 

There is a wide range of polyacrylic acids, polymethacrylic acids, their salts, and polymer derivatives available from many manufacturers around the world today. These products remain the backbone of chemical formulations in the cooling water treatment industry. They are manufactured with an almost infinite variety of average molecular weights, molecular weight distributions, activity strengths, and other characteristics. 

Grafted cellulose powders such as Solka Floe have been grafted with polyacrylic acid and also rendered cationic by direct chemical reaction (54). Both of these modified cellulose products have been prepared on a large scale. They appear to show considerable promise for the removal of dyestuffs and other charged impurities from waste water such as textile effluents. They are also able to break emulsions of water and organics by removal of the surfactants (55). 

When hydrolyzed in water, the resulting diacid exhibits two pKs ( 3 and 8) the half ester as expected has one pKa typical of polycarboxylic acids. A cross-linked version of this polymer, referred to as Stabileze, thickens a variety of formulations by expanding its hydrodynamic volume when neutralized. Because of the low pKa of the vicinal diacids, Stabileze acquires a negative charge at lower pH than competitive cross-linked polyacrylic acids (carbomers). This allows for efficient thickening at lower pHs similar to that found on moist skin, which in turn allows products to perform at optimum pH as desired by skin-care product formulators (63). 

The acrylic plastics use the term acryl such as polymethyl methacrylate (PMMA), polyacrylic acid, polymethacrytic acid, poly-R acrylate, poly-R methacrylate, polymethylacrylate, polyethylmethacrylate, and cyanoacrylate plastics. PMMA is the major and most important homopolymer in the series of acrylics with a sufficient high glass transition temperature to form useful products. Repeat units of the other types are used. Ethylacrylate repeat units form the major component in acrylate rubbers. PMMAs have high optical clarity, excellent weatherability, very broad color range, and hardest surface of any untreated thermoplastic. Chemical, thermal and impact properties are good to fair. Acrylics will fail in a brittle manner, independent of the temperature. They will suffer crazing when loaded at stress about halfway to the failure level. This effect is enhanced by the presence of solvents. 

Polymerization on the matrix is 63 times more rapid than polymerization of dimers [64]. The product is a stereo block polymer of the syndiotactic and atactic polyacrylic acid configurations. When hydrocarbons or their chlorinated derivatives are used as solvent, the matrix effect does not occur. 

PVA, CMC, caprolactam oligomers, ethoxylated products, sulfonates, polyacrylic acid or adipic acid copolymers... 

Betaxolol is suppUed as a sterile suspension of 0.25% betaxolol HCl (Betoptic-S). The suspension is a unique formulation containing a polyacrylic acid polymer (carbomer 934P) and a cationic exchange resin, which is beUeved to increase the drug residence time in the eye (see Chapter 2). This product is the racemic compoimd, preserved with 0.01% BAC, and approved for twice-daily use. 

For more than decades, acrylic acid has served as an essential building block in the production of some of our most commonly used industrial and consumer products. Approximately two-thirds of the acrylic acid manufactured in the United States is used to produce acrylic esters - methyl acrylate, butyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate -which, when polymerized, are ingredients in paints, coatings, textiles, adhesives, plastics, and many other applications. The remaining one-third of the acrylic acid is used to produce polyacrylic acid, or cross-linked polyacrylic acid compounds, which have been successfully used in the manufacture of hygienic... 

Various synthetic substances are able to stimulate interferon production, some of them only in vivo (polycarboxylates pyran copolymer, polyacrylic acid, chlorite-oxidized oxyamylose low molecular weight compounds tilorone,... 

When making very dehcate materials it may be necessary to use a yam which is so fine that it would break down under the stresses imposed on it during manufacture. The strength, however, is sufficient once the fabric is made because of the mutual support of adjacent threads. In such cases it is customary to impart temporary strength to the yam by a process known as sizing. This consists of impregnating the thread with some easily removed substance such as starch or dextrine and, in the case of the more modern man-made fibres, with a synthetic product such as polyvinyl alcohol or polyacrylic acid. The size is usually removed before the article is dyed or bleached. Yarns are frequently referred to as warp or weft yarns. In a... 

The mechanical properties of the surface-modified products were examined by a special shear test. After reactive surface modification under optimised chemical and technological conditions, the test specimens were cut and the pieces were bonded by special adhesives. The coimected pieces were examined in a shear test and the shear strength was determined in dependence on the chemical and processing conditions. The best results for polyamides were obtained for polyacrylic acid as the modifier with an increase of the shear strength from 28 MPa (non-modified polyamide) up to 37 MPa for polyacrylic acid-modified polyamide surfaces. 

Currently, products in the market are thickened mainly by polyacrylic acids, although some use a mixture of polymer and a clay. This is in contrast to the early LADD products, which used exclusively clay thickeners and therefore suffered from stability problems [7], The products, being clay suspensions in an aqueous medium, tended to separate in a relatively short period of time. The introduction of bleach-compatible polymeric thickeners in the early 1990s overcame this problem [75],... 

Addition of polyacrylic acid at pH 5.0 to the former solvent (the aqueous solution of 10 3 mol/L KC1 and 10 4 mol/L A1C13 at pH 5.0) induced a fast pH drop whose amplitude is related to the degree of acid complexation. The hydrogen ion production during complex formation might be interpreted on the basis of the reaction [80]... 

Sulfosuccinic and sulfopropionic acids are economically attractive when synthesized in situ or offsite from maleic anhydride or acrylic acid. Both are subject to oxidation, but should give nonvolatile degradation products. Synthesis of sulfopropionic acid can give undesirable polyacrylic acid impurities. 

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