Hydrolyzed-polyacrylonitrile

Electrical charge density is increased, such as sulfonated phenolic resin, carboxymethylcellulose, and hydrolyzed polyacrylonitrile... 

Aqueous solutions of polyacrylamide may be used as plugging solutions for high-permeability formations. Partially hydrolyzed polyacrylamide polymer also has been used [1211] and completely hydrolyzed polyacrylonitrile has been proposed [1427]. 

Hydrolyzed polyacrylonitrile Waste from lanolin production treated with triethanol amine and water [1427]... 

Partially hydrolyzed polyacrylonitrile/l-poly(acrylic acid) blend layer membrane... 

Y. Maeda, M. Tsuyumoto, H. Karakane and H. Tsugaya, Separation of water-ethanol mixture by pervaporation through hydrolyzed polyacrylonitrile hollow fiber membranes, Polymer J., 1991, 23, 501-512 N. Schamagl, K.-V Peinemann, A. Wenzlaff, H.-H. Schwarz and R.-D. Behling, Dehydration of organic compounds with SYM-PLEX composite membranes, J. Membr. Sci., 1996, 113, 1-5. 

Y. Maeda, M. Tsuyumoto, H. Karakane and H. Tsuyumoto, Separation of water-ethanol mixture by pervaporation through hydrolyzed polyacrylonitrile hollow fiber membranes, Polym. J., 1991, 23, 501-511. 

Siskin et al. similarly hydrolyzed polyacrylonitrile to low-molecular-weight oligomeric materials, with the generation of ammonia instead of the toxic hydrogen cyanide formed by conventional thermolysis processes. Holliday et al. reported that triglyceride-based vegetable oils can be hydrolyzed into their fatty acids constituents. The authors studied NCW and SCW. Although the conversion yields are comparable in both medium, NCW... 

Yang, M.-C., and Tong, J.-H. (1997). Loose ultrafiltration of proteins using hydrolyzed polyacrylonitrile hollow fiber. J. Membr. Sci. 132, 63. 

Tauber MM, A Cavaco-Paulo, K-H Robra, GM Gubitz (2000) Nitrile hydratase and amidase from Rhodococ-cus rhodochrous hydrolyze acrylic fibers and granular polyacrylonitrile. Appl Environ Microbiol 66 1634-1638. 

There are two pathways for the degradation of nitriles (a) direct formation of carboxylic acids by the activity of a nitrilase, for example, in Bacillus sp. strain OxB-1 and P. syringae B728a (b) hydration to amides followed by hydrolysis, for example, in P. chlororaphis (Oinuma et al. 2003). The monomer acrylonitrile occurs in wastewater from the production of polyacrylonitrile (PAN), and is hydrolyzed by bacteria to acrylate by the combined activity of a nitrilase (hydratase) and an amidase. Acrylate is then degraded by hydration to either lactate or P-hydroxypropionate. The nitrilase or amidase is also capable of hydrolyzing the nitrile group in a number of other nitriles (Robertson et al. 2004) including PAN (Tauber et al. 2000). 

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) ... 

Esters of poly(carboxylic acids), nitrites, and amides may be hydrolyzed to produce poly (carboxylic acids). Thus, polyacrylonitrile, polyacrylamide, or poly(methyl acrylate) may be hydrolyzed producing poly(acrylic acid) (equation 16.2). 

The degradation of the cellulose fraction of the copolymer and subsequent recovery of the polyvinyl polymer have often been used to characterize the polymer. For example, cellulose may be acetylated and acid hydrolyzed to remove it from the copolymer. Then the recovered polymer can be dissolved, in solvent normally used for the polymer, and i the molecular weight of the polymer determined viscometrically (12, 42). As reported previously for polymers, such as polyacrylonitrile, a functional group on the polymer may be altered during the fractionating. These changes have been determined by infrared spectroscopy. For free-... 

Molecular Weight of Grafted PAN Chains. A homopolymer-free graft copolymer sample was hydrolyzed in 2 M HC1 for 48 h at room temperature to depolymerize the cellulose chains. The residue, mainly polyacrylonitrile (PAN) chains, was washed with water and... 

Polymers with pendant groups that are derivatives of carboxylic acid can he hydrolyzed to yield poly(acrylic acid). This includes polymers like polyacrylamide, polyacrylonitrile, and polyacrylates. When heated, poly(acrylic acid) form polymeric anhydrides, which undergo typical reactions of anhydrides, such as hydrolysis, alcoholysis, and amidation. 

Polyacrylamides are also suitable for a variety of biomedical uses the structure of polyacrylamide is shown in Fig. IG, although the use of acrylamides in copolymers is much more common. Polyvinylpyrrolidinone has also found use as a biocompatible coating material (Fig. IH). Polyacrylonitrile, though not suitable in itself, can be hydrolyzed to form some hydrophilic polymers such as the Hypan (Hymedix Inc.) series of hydrogels. 

Benzonitrile acts in a similar way to form benzoic acid but requires sulfuric acid in the reacting mixture. Nicotinic acid amide (nicotinamide) has been prepared by the mild hydrolysis of 3-cyanopyridine, and acrylamide by the partial hydrolysis of acrylonitrile. Acrylonitrile may also be hydrolyzed to acrylic acid with mineral acids or with alkalies. Polyacrylonitrile is partially converted to the amide by nitric acid, and the nitrile oups of a number of polymers and copolymers have been hydrolyzed to amide and carboxylic acid groups to produce water-soluble polyelectrolytes. Isooyanides are stable toward alkalies but hydrolyze in the presence of acids to form an acid and an amine ... 

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). 

An enzymatic production process for Diltiazem (54), a coronary vasodilator and calcium channel blocker, was started in 1993 by Tanabe Seiyaku, Japan [7, 77]. The epoxide (2i, 3S)-52 is a key intermediate in this synthesis (Scheme 17) and can be produced via asymmetric hydrolysis of rac-52 catalyzed by Serratia marescens lipase immobilized on spongy layers. The whole process takes place in a polyacrylonitrile hollow fiber membrane reactor and produces (2i, 3S)-52 in yields of 40-45%. The hydrolyzed product (2S,3i )-53 is not stable under the prevailing reaction conditions and decarboxylates to aldehyde 55, a strong enzyme deactivator. The aldehyde needs therefore to be removed, which is achieved by continuous filtration of its bisulfite adduct 56. Using this enzymatic process it was possible to bring down the number of required steps en route to 54 from nine to five. This process is also carried out by other companies (e.g., DSM) with a worldwide annual production of 1001. 

Chen et al. (2009) functionahzed polyacrylonitrile (PAN) nanofibers so as to enable their use in the development of self-detoxifying chemical protection fabrics. The authors reacted PAN nanofibers with excess of hydroxylamine in methanol at 70 °C. The oximation of the nanofiber mats resnlted in the formation of polyaciylamidoxime on the snrface of the fibers. The authors proved that the functionalized nanofibers snccessfully hydrolyzed diisopropyl fluorophosphate (DFP) in the presence of water. The rate constant of the pseudo-first order reactions was found to increase with the presence of water in the nanofiber mats. According to the authors, the water in the mats facihtates the nucleophilic attack of amidoximes to accelerate the decomposition of DFP." ... 

Most synthetic polymers lie between these two extremes. Typical step-reaction polymers, such as polyesters, polyamides, polycarbonates, polsnirethanes, and cellulose esters, all contain hydrolyzable groups in the main chain. On the other hand, many chain reaction polymers, such as polyacrylonitrile, PMMA, and PVC, contain substituent groups which may hydrolyze at appropriate pH. 

In addition to synthetic appHcations, the NHase/amidase cascade can also be used in post-production processes, like enhancing structure and properties of (poly)acryhc fibers. Tauber et al. [43] showed that the NHase and amidase of R. rhodochrous NCIMB 11216 were able to hydrolyze nitrile groups of both granular polyacrylonitriles (PANs) and acrylic fibers. The acrylic fibers became more hydrophihc because of the enzymatic modification, enhancing the adsorption of dyes. 

Polyacrylonitrile is hydrolyzed by heating with concentrated aqueous sodium hydroxide to poly(sodium acrylate). 

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