Starch-polyacrylonitrile

A recently developed class of compounds called Super Slurpers based on starch- polyacrylonitrile copolymers are able to absorb as much as 500 to 1000 times their weight of water, depending on the purity of the water (19, 20, 21). The formation of these copolymers is catalyzed by Ce ion. These polymers were developed by the U.S, Department of Agriculture and have potential agricultural uses as water storage additives as well as obvious consumer and industrial applications. 

Previous work has shown that gels formed from cross-linked polyacrylamide (6), alginate (6), hydrolyzed starch-polyacrylonitrile (7), and a cross-linked poly(acrylic acid) (8), consist of discontinuous structures with microregions of extremely low viscosity. Such microscopic heterogeneity has been attributed to permanent or diffusing fluctuations within the gel (i) or to a structure of closely packed, swollen microgels in a continuous water phase (2, 3). 

Yamaguchi M, Watomoto H, Sakamoto M (1987) Super-absorbent polymers from starch-polyacrylonitrile graft copolymers by acid hydrolysis befine sapmiification. Carbohydr Polym 7 71-82... 

Smith T (1972) Water absorbing alkali metal carboxylate salts of starch-polyacrylonitrile... 

Gugliemelli LA, Swanson CL, Baker FL, Doane WM, Russell CR. 1974. Cationic starch-polyacrylonitrile graft copolymer latexes. J Polym Sd, Polym Chem Edit 12 2683-2692. 

The second group includes SAHs obtained by radical grafting of acrylonitrile (AN) on natural polymers, mostly starch, under the action of cerium initiators [43 -46, 50, 51], The proper crosslinked hydrophilic polymer is formed at the stage of alkali hydrolysis of grafted polyacrylonitrile (PAN), the final characteristics depending on many factors, in particular the sort of starch [46], the methods of its preparation [51], the component ratio, etc. The nature of starch is exhibited through... 

Starch (1), Cellulose (2), Cellulose Methyl Ether (3), Oxy-cellulose (4), PVA (5), Partially Hydrolyzed PVAc (6), Silk (.2), Wool (7), Hide-Powder (8), Natural Rubber Latex ( ), Synthesized Poly-(ot-Amino Acids) (10), Nylon-6 (11), Nylon-3 (12), Ot-Amylase (13), Lysozyme (14), RNA (15), Polyacrylonitrile (16), Polyvinyl-sulfonate (17) ... 

Saroja, N., Shamala, T. R., Tharanathan, T. R. (2000). Biodegration of starch-g-polyacrylonitrile, a packaging material, by Bacillus cereus. Process Biochem., 36, 119-125. 

Superabsorbent polymers are now commonly made from the polymerization of acrylic acid blended with sodium hydroxide in the presence of an initiator to form a polyacrylic acid, sodium salt (sometimes referred to as cross-linked sodium polyacrylate). Some of the polymers include polyacrylamide copolymer, ethylene maleic anhydride copolymer, cross-linked carboxy-methyl-cellulose, polyvinyl alcohol copolymers, cross-linked polyethylene oxide, and starch grafted copolymer of polyacrylonitrile to name a few. The latter is one of the oldest SAP forms created. 

Acrylonitrile graft polymerizes readily with either granular or pasted starch to yield starch-g-polyacrylonitrile (PAN), and reactions are generally carried out in water with ceric ammonium nitrate as the initiating system CL). Reaction of starch-g-PAN with alkali at elevated temperatures converts the nitrile substituents of PAN to a mixture of carboxamide... 

Starch phosphate was combined with rosin and alum to increase the dry strength and ink retention characteristics of paper.1677 Starch phosphates have also been used as soil conditioners to increase water retention.1678 Starch phosphates improved the dispersion and dye reception of synthetic fibers,1667 and are used to stabilize water,1543 finger paints,1679 and white coating colors.1680 Phosphonoamidated starches are useful in paper sizing.1681 Biodegradable films were produced by combining starch phosphate with poly (vinyl alcohol).1682 Phosphonoacetyl starch added to polyacrylonitrile improved it affinity for dyes.1683... 

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