Superabsorbent polymers applications

Hydrogels, 13 729-759. See also Microgels Superabsorbent polymers (SAPs) AMPS polymer, 23 721 applications for, 13 747-753 biodegradable, 13 739-742 bioerodible, 9 63 conducting, 7 524 cross-linked poly (ethylene oxide),... 

Fushimi T (1990) Ideas of Applications of Superabsorbent Polymers (in Japanese). Kogyo Chosaki, Tokyo... 

Another important bulk chemical that could be derived from glycerol is acrylic acid (Craciun et al., 2005 Shima and Takahashi, 2006 Dubois et al., 2006). Shima and Takahashi (2006) reported a complete process for acrylic acid production involving the steps of glycerol dehydration in a gas phase followed by the application of a gas phase oxidation reaction to a gaseous reaction product formed by the dehydration reaction. Dehydration of glycerol could lead to commercially viable production of acrolein, which is an important and versatile intermediate for the production of acrylic acid esters, superabsorber polymers or detergents (Ott et al., 2006). Sub- and supercritical water have been applied by Ott et al. (2006) as the reaction media for glycerol dehydration, but the conversion and acrolein selectivities that have been achieved so far are not satisfactory for an economical process. 

Superabsorbents. Water-swellable polymers are used extensively in consumer articles and for industrial applications. Most of these polymers are cross-linked acrylic copolymers of metal salts of acrylic 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). 

Woven cloth, cotton wadding, cellulose fiber batt, papers, and foamed polyurethane have been used as traditional absorbent materials for water. These materials can absorb 1-20 g of water per gram material and the water absorbed is easily removed from the materials by applying low pressure. In recent years, superabsorbent polymers, which can absorb up to 1000 g of water per gram of polymer and up to about 100 g of dilute salt solution per gram of polymer and the water absorbed can hardly be removed from the polymers even by applying high pressure, have been prepared and commercially used in many applications. 

Superabsorbents are superabsorbent polymers, which are loosely crosslinked hydrophilic polymers and have ionic charges in the polymers. They absorb water, swell, and retain aqueous solution above hundred times their own weight. Because of the excellent characteristics, the superabsorbents have been widely used in many applications such as disposable diapers, feminine napkins, soil additives in agricultural or horticultural applications, gel actuators, water-blocking tapes, materials for drug delivery system, absorbent pads, etc., where water absorbency or water retention is important. 

Superabsorbent polymers have been used in a variety of fields. In Table 3, the applications of superabsorbent polymers are listed. 

Buchholz, F.L. Application of superabsorbent polymers. In Modem Soperabsorbent Polymer Technology, Buchholz, F.L., Graham, A.T., Eds. Wiley-VCH New York, 1997 251-272. Nishizawa, K. Shirase, T. Mizutani, H. Moisture-Permeable Disposable Diapers. U.S. Patent 4,306,559, December 22, 1981. 

Levy, R., M.A. Nichols, T.W. Miller Jr., Evaluation of superabsorbent polymer-pesticide formulations for prolonged insect control, in RR. Hall, P.D. Berger, and H.M. Collins (eds.). Pesticide Formulations and Application Systems, ASTM STP 1234, American Society for Testing and Materials, Philadelphia, PA, 1995, pp. 330-339. 

Cassava starch-based blend films, and superabsorbent polymers were developed and their potential in specific applications was studied. Starch-konjac glucoman-... 

Huttermann, A. Orikiriza, L. J. B. Agaba, H. Application of superabsorbent polymers for improving the ecological chemistry of degraded or polluted lands. Clean-Soil Air Water 37 517-526... 

McAirlaid s has been one of the leaders in soaker pads with their special SuperCore airlaid material for fish, poultry and meat applications. They are also able to produce tailored grades for advanced applications that can incorporate superabsorbent polymers or superabsorbent fibres. 

Superabsorbent polymers have also found limited utility as additives to soil to improve the water-holding ability. The hydogel absorbs the water and controls its release back into the soil as conditions become drier. Poly(ammonium acrylate) and poly(acrylamide) hydrogels have been studied for spray application to the soil and plants. The gels are prepared for spraying by adding water to provide a readily deformable polymer that will pass... 

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