2- -2-methylpropanesulfonic acid

Superabsorbents. Water-sweUable polymers are used extensively in consumer articles and for industrial appUcations. Most of these polymers are cross-linked acryUc copolymers of metal salts of acryUc acid and acrylamide or other monomers such as 2-acrylamido-2-methylpropanesulfonic acid. These hydrogel forming systems can have high gel strength as measured by the shear modulus (134). Sometimes inorganic water-insoluble powder is blended with the polymer to increase gel strength (135). Patents describe processes for making cross-linked polyurethane foams which contain superabsorbent polymers (136,137). 

Acrylonitrile has been grafted onto many polymeric systems. In particular, acrylonitrile grafting has been used to impart hydrophilic behavior to starch (143—145) and polymer fibers (146). Exceptional water absorption capabiUty results from the grafting of acrylonitrile to starch, and the use of 2-acrylamido-2-methylpropanesulfonic acid [15214-89-8] along with acrylonitrile for grafting results in copolymers that can absorb over 5000 times their weight of deionized water (147). 

These monomers impart hydrophilicity as a result of the presence of polar —OH and —CONH— groups. Acid-containing monomers, such as methacrylic acid [79-41-4] (MAA), and 2-acrylamido-2-methylpropanesulfonic acid [15214-89-8] provide ionic character at pH above 7.0 and contribute a large amount of water absorption. 

Morishima etal. [29 — 31] prepared amphiphilic copolymers of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) with various hydrophobic comonomers, and studied the tendency of their self-aggregation and the nature of the hydrophobic microdomains thus formed in aqueous solution. Chart 1 shows some of these amphiphilic copolymers. Here, the value of x indicates the mol% content of hydrophobic comonomer units. 

As has been described in Chapter 4, random copolymers of styrene (St) and 2-(acrylamido)-2-methylpropanesulfonic acid (AMPS) form a micelle-like microphase structure in aqueous solution [29]. The intramolecular hydrophobic aggregation of the St residues occurs when the St content in the copolymer is higher than ca. 50 mol%. When a small mole fraction of the phenanthrene (Phen) residues is covalently incorporated into such an amphiphilic polyelectrolyte, the Phen residues are hydrophobically encapsulated in the aggregate of the St residues. This kind of polymer system (poly(A/St/Phen), 29) can be prepared by free radical ter-polymerization of AMPS, St, and a small mole fraction of 9-vinylphenanthrene [119]. 

Hydrolysis of amide groups to carboxylate is a major cause of instability in acrylamide-based polymers, especially at alkaline pH and high temperatures. The performance of oil-recovery polymers may be adversely affected by excessive hydrolysis, which can promote precipitation from sea water solution. This work has studied the effects of the sodium salts of acrylic acid and AMPS, 2-acrylamido-2-methylpropanesulfonic acid, as comonomers, on the rate of hydrolysis of polyacrylamides in alkaline solution at high temperatures. Copolymers were prepared containing from 0-53 mole % of the anionic comonomers, and hydrolyzed in aqueous solution at pH 8.5 at 90°C, 108°C and 120°C. The extent of hydrolysis was measured by a conductometric method, analyzing for the total carboxylate content. 

Materials. Monomers used in the preparation of the copolymers were as follows acrylamide as a 50% solution in water, stablized with cupric ion, supplied by American Cyanamid Company acrylic acid supplied by BASF and AMPS, 2-acrylamido-2-methylpropanesulfonic acid, (recrystallized grade) obtained from Lubrizol. The sodium salts of acrylic acid and AMPS were prepared by gradual neutralization of the monomers with sodium hydroxide solution, maintaining a temperature of 0 to 5°C, to give a final concentration of 50%. 

The rate of hydrolysis of acrylamide in copolymers with sodium acrylate or AMPS, 2-acrylamido-2-methylpropanesulfonic acid, decreased as the proportion of the anionic comonomers was increased. This effect was much more marked with AMPS than with sodium acrylate, and occurred at 90°, 108°, and 120°C. Typical results at 108°C [Figs. 1 and 2] show the increase in carboxylate content of acrylamide copolymers containing sodium acrylate and AMPS respectively. 

Saponified Starch-g-pofy(acrylonitrile-co-2-acrylamido-2-methylpropanesulfonic acid) Influence of Reaction Variables on Absorbency and Wicking... 

Sulfonated styrene, maleic anhydride (SS/MA) has proved to be a popular inhibitor for calcium phosphate control in stabilized phosphate and other polyphosphate programs. As such, it competes with other calcium phosphate control technologies, such as acrylic acid, hydroxypropyl acrylate copolymer (AA/HPA) and acrylic acid, 2-acrylimido-2-methylpropanesulfonic acid (AA/AMPS, or sometimes known as AA/SA), and acrylic acid, sodium 3-allyloxy-2-hydroxypropane sulfonate copolymer (AA/COPS). 

Osada et al. [252] studied the complexation of 23b with poly(2-acrylamido-2-methylpropanesulfonic acid) (polyAMPS), quaternized polyN-[3-(dime-thylamino)propyl]acrylamide chloride (PDMAPAA-Q), and x,y-ionene bromides (x = 3,6 = 3,4) in aqueous solution. Depending on the concentration and the mixing ratio of the constituent polymers, water-soluble IPCs were formed which exhibit an UCST, Uke the parent polybetaine. The UCST decreased markedly when a small amount of the polyanion polyAMPS was added to the solution of 23b, and eventually disappeared at high concentrations of polyAMPS. 

A perfectly linear pH gradient was immobilized across a 10-cm polyacrylamide gel using pK 7.0 3-morpholinopropylacrylamide titrated with 2-acrylamido-2-methylpropanesulfonic acid. This gel was used to focus a mixture of three Hb variants, with pi values of 7.42 (Hb A2), 7.21 (Hb S), and 7.05 (Hb F). Calculate the positions of the three focused bands as distances from the cathodic end of the gel. 

Recently, Tong and Liu [50] also attempted to examine carefully the HID theory with their swelling experiments for copolymer gels of ALV-dimcthyl-acrylamide (DMAAm) and 2-acrylamide-2-methylpropanesulfonic acid (AMPS). They used Eqs. 8 and 9 for the II of Eq. 1, which was obtained according to the HID theory ... 

Sulfonation was carried out by heating the asphalt with sulfur trioxide-trimethyl amine complex or sulfur trioxide-pyridine complex at temperatures near 135°C. Sulfamic acid treatment was also included in this series. Many other reagents were evaluated such as methyl methacrylate, 2-acrylamido-2-methylpropanesulfonic acid, 2-dimethyl-aminoethyl methacrylate, 2-vinylpyridine, 4-vinylpyridine, tetrahydro-phthalic anhydride, norbomene dicarboxylic anhydride, and phthalic anhydride. 

Acrylamido)-2-methylpropanesulfonic acid is a useful reagent for the preparation of such compounds.1831 Side-chain substituted sulfones were prepared by reacting starch with corresponding vinyl sulfones. A basic catalyst is needed to perform these reactions in various solvents (such as diethyl ether, chloroform, benzene, and water).1757... 

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