Polyacrylate salts

Suitable protective coUoids for the preparation of acryhc suspension polymers include ceUulose derivatives, polyacrylate salts, starch, poly(vinyl alcohol), gelatin, talc, clay, and clay derivatives (95). These materials are added to prevent the monomer droplets from coalescing during polymerisation (110). Thickeners such as glycerol, glycols, polyglycols, and inorganic salts ate also often added to improve the quahty of acryhc suspension polymers (95). 

X-ray diffraction shows that both the cement matrix and the salt are amorphous (Wilson, 1982 Smith, 1971 Steinke et al., 1988). On the basis of chemical analysis, Wilson (1982) assigned the following empirical formula to the zinc polyacrylate salt ... 

He compared the infrared spectra of cements with that of zinc polyacrylate salt and found differences. Inspection of his data shows that, unlike the cements, the salt was purely ionic, so that it seems here that cement formation is associated with the formation of coordination complexes. There are no ligand field stabilization effects with the Zn ion because it has a completed d shell (Cotton Wilkinson, 1966). For this reason the... 

Two matrices are formed a metal polyacrylate salt and a polymer. There is a lack of water in the system because some of it has been replaced by HEM A, and lack of water in glass polyalkenoate cements is known to slow down the ionomer add-base reaction (Hornsby, 1977). Thus, the initial set of these materials results from the polymerization of HEMA and not the characteristic acid-base reaction of glass-ionomer cements. The later reaction serves only to harden and strengthen the already formed matrix. 

Polymerization of HEMA is affected by the presence of the other components of resin-modified glass-ionomers. It has been shown that HEMA itself will undergo addition polymerization more rapidly in the presence of poly(acrylic acid) than on its own [18]. However, in resin-modified glass-ionomers, pure unreacted poly(acrylic acid) may not be present for very long, and the effect of metal polyacrylate salts on the rate of polymerization of HEMA has not been studied. 

Chem. Descrip. Sodium polyacrylate salt in water CAS 9003-04-7... 

JOH Johansson, H.-O., Feitosa, E., and Pessoa, A., Phase diagrams of the aqueous two-phase systems of poly(ethylene glycol)/sodium polyacrylate/salts. Polymers, 3, 587, 2011. 

Acrylate and acrylamide polymers have several uses in drilling fluids, one of which is for filtration control. Sodium polyacrylates [9003-04-7] having molecular weights near 250,000 are exceUent temperature-stable filtration control agents for both fresh- and salt water muds, provided the concentration of water-soluble calcium is <400 mg/L (83). The calcium ions are precipitated using a carbonate such as soda ash, before adding the polyacrylate at concentrations up to ca 6 kg/m (3 Ib/bbl). 

Other Accelerators. Amine isophthalate and thiazolidine thione, which are used as alternatives to thioureas for cross-linking polychloroprene (Neoprene) and other chlorine-containing polymers, are also used as accelerators. A few free amines are used as accelerators of sulfur vulcanization these have high molecular weight to minimize volatility and workplace exposure. Several amines and amine salts are used to speed up the dimercapto thiadiazole cure of chlorinated polyethylene and polyacrylates. Phosphonium salts are used as accelerators for the bisphenol cure of fluorocarbon mbbers. 

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. 

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... 

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. 

All of these various homopolymeric carboxylates may form soluble complexes with hardness salts in BW, similar to EDTA and NTA. However, using polyacrylates in dirty boilers with a considerable excess of iron or calcium may cause metal acrylate deposition. 

Polycondensation pol5mers, like polyesters or polyamides, are obtained by condensation reactions of monomers, which entail elimination of small molecules (e.g. water or a hydrogen halide), usually under acid/ base catalysis conditions. Polyolefins and polyacrylates are typical polyaddition products, which can be obtained by radical, ionic and transition metal catalyzed polymerization. The process usually requires an initiator (a radical precursor, a salt, electromagnetic radiation) or a catalyst (a transition metal). Cross-linked polyaddition pol5mers have been almost exclusively used so far as catalytic supports, in academic research, with few exceptions (for examples of metal catalysts on polyamides see Ref. [95-98]). 

Polyacrylic acid, or a water-soluble salt, having a molecular weight of 1500 to 5000, measured on the respective sodium salt and a polydispersity of 1.05 to 1.45, has been described as a dispersant for a drilling or packer fluid [576]. 

Small counterions (gegenions) ensure electroneutrality. For example, the sodium salt of polyacrylic acid is ionized in solution to form polyanions and the corresponding number of sodium cations ... 

Scale inhibitors are used to prevent the formation of insoluble calcium salts when the drilling fluid contacts formation minerals and saline formation waters. Commonly used scale inhibitors include sodium hydroxide, sodium carbonate, sodium bicarbonate, polyacrylates, polyphosphates, and phosphonates. 

Polyelectrolytes are long chain molecules bearing ionisable sites. It is not always possible to predict with confidence the extent to which polyelectrolytes behaviour is exhibited. Thus, polyacrylic acid in water is only weakly ionised and in dioxan it behaves as a typical non-electrolyte. It is usual to overcome the complications imposed by ionic interactions by the inclusion of simple salts and LS studies in salt-free solutions are rather rare. The problems have been discussed recently by Kratochvil137), whilst the review of Nagasawa and Takahashi138 constitutes one of the few devoted exclusively to LS from polyelectrolyte solutions. LS from many biopolymers such as proteins is, of course, extremely relevant in this context. 

What happened when you added the salt Come up with an explanation for what you observed. Search for a discussion of sodium polyacrylate on the Internet to check your explanation. 

A polyelectrolyte solution contains the salt of a polyion, a polymer comprised of repeating ionized units. In dilute solutions, a substantial fraction of sodium ions are bound to polyacrylate at concentrations where sodium acetate exhibits only dissoci-atedions. Thus counterion binding plays a central role in polyelectrolyte solutions [1], Close approach of counterions to polyions results in mutual perturbation of the hydration layers and the description of the electrical potential around polyions is different to both the Debye-Huckel treatment for soluble ions and the Gouy-Chapman model for a surface charge distribution, with Manning condensation of ions around the polyelectrolyte. 

Acrylic acid and its salts are raw materials for an important range of esters, including methyl, ethyl, butyl, and 2-ethylhexyl acrylates. The acid and its esters are used in polyacrylic acid and salts (32%, including superabsorbent polymers, detergents, water treatment chemicals, and dispersants), surface coatings (18%), adhesives and sealants (15%), textiles and non-wovens (12%), plastic modifiers (5%), and paper coating (3%). 

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