Acrylonitrile copolymers, membrane

The present contribution describes a novel low pressure, high flux system which utilizes an "in situ" dynamically formed silica membrane particularly suited for the ultrafiltration of emulsions. The support for this selective layer of silica was a pleated, thin channel crossflow module il (tradename "Acro-flux", Gelman Sciences, Inc.) containing 0.1 m of 0.2 urn pore size acrylonitrile copolymer membrane. 

Vasileva, N., Godjevargova, T, Ivanova, D. and Gabrovska, K. 2009. Application of immobilized horseradish peroxidase onto modified acrylonitrile copolymer membrane in removing of phenol from water. Intematioruil Journal of Biological Macromolecules, 44,190-194. 

Gabrovska K, Nedelcheva T, Godjevargova T, Stoilova O, Manolova N, Rashkov I (2008) Immobilization of acetylcholinesterase on new modified acrylonitrile copolymer membranes. J Mol Catal B 55 169-176... 

BP. These nitrile alloy membranes are compounded from PVC, flexibilized by the addition of butadiene—acrylonitrile copolymers, PVC, and other proprietary ingredients. Typically reinforced with polyester scrim, NBP membranes are 1 mm thick and have a width of 1.5 m. They ate ptedominandy used in mechanically fastened roofing systems. NBP membranes exhibit excellent teat and puncture resistance as well as good weatherabihty, and remain flexible at low temperatures. They ate resistant to most chemicals but ate sensitive to aromatic hydrocarbons. The sheet is usually offered in light colors. The physical characteristics of NBP membranes have been described (15). 

Membrane stmcture is a function of the materials used (polymer composition, molecular weight distribution, solvent system, etc) and the mode of preparation (solution viscosity, evaporation time, humidity, etc). Commonly used polymers include cellulose acetates, polyamides, polysulfones, dynels (vinyl chloride-acrylonitrile copolymers) and poly(vinyhdene fluoride). 

In many cases the organic to be dehydrated (e.g., acetic acid) attacks the ether linkage in the PVA membrane. Indeed, the PVA membrane has very limited fife in the presence of most acids. Ray et al. [14] used the concept of copolymer membranes to dehydrate acetic acid over the entire range of concentration from 0% to 100%. These investigators prepared copolymers of acrylonitrile (AN) with different hydrophUic monomers like hydroxy ethyl methacrylate, acrylic acid, methacrylic acid, and itaconic acid. These copolymers have carbon-carbon bonds, which unlike the ether linkage in the cross-hnked PVA membrane are stable to the attack by carboxyhc acids. The acrylonitrile part is not sufficiently hydrophihc but imparts mechanical strength while the other monomers improve the hydrophilicity. The overall result is an efficient yet stable membrane. Variation of the ratio of AN to (the other) monomer allows freedom of adjusting the hydrophUicity of the membrane to achieve certain... 

Acrylamide-acrylic acid copolymer gel prepared in porous of ceramic thin membrane Acrylonitrile-vinyl compounds copolymer membrane... 

Organic-organic and organic compounds/water separation Acrylonitrile-vinyl compounds copolymer membrane a = 1747 for 80% aqueous acetic acid at 70°C [78]... 

Mandal S and Pangarkar VG. Pervaporative dehydration of l-methoxy-2-propanol with acrylonitrile based copolymer membranes prepared through emulsion polymerization A solubility parameter approach and study of structural impact. J. Memb. Sci. 2002 209(l) 53-66. 

Ray S and Ray SK. Dehydration of acetic-acid, alcohols and acetone by pervaporation using acrylonitrile-maleic anhydride copolymer membrane. Sep. Sci Tech. 2005 40(8) 1583-1596. 

Mandal S, Pangarkar VG. 2005. Acrylonitrile based copolymer membranes for the separation of methanol from methanol-toluene mixtmes through pervaporation. J. Appl. Polym. Sci 96 243-252. 

Kobayashi, T. Wang, H.Y. Fujii, N. Molecular imprinting of theophylline in acrylonitrile-acrylic acid copolymer membrane. Chem. Lett. 1995, 10, 927-928. 

The copolymerization of acrylic esters with 5%-15% acrylonitrile or 2-chloroethyl vinyl ether produces elastomers which are more heat and oxidation resistant than butadiene/acrylonitrile copolymers because of the absence of double bonds. For the same reasons, these materials are also suitable for the manufacture of gaskets and membranes for use with high-sulfur-content industrial oils (for example, crankshaft gaskets in the automobile industry). Since the side groups have poor resistance to hydrolysis, steam curing is not possible. Curing with amines can be subsequently carried out. 

Nie, F.Q., Xu, Z.K., Huang, X.J., Ye, P. and Wu, J. 2003. Acrylonitrile-based copolymer membranes containing reactive groups Surface modification by the immobilization of poly(ethylene glycol) for improving antifouling property and biocompatibility. LanemuirWrny. 9889-9895. 

New copolymer membranes of acrylonitrile for the separation of benzene-CYH mixtures by PV were developed by Ray et al. (1997). The monomers in the copolymers were selected on the basis of their solubility parameter values relative to those of benzene and CYH. These were styrene, methyl methacrylate, and vinyl acetate. Copolymers of acrylonitrile with methyl methacrylate and vinyl acetate showed good selectivity and moderate flux 60-70 and 0.075 kg/m h, respectively, with a membrane of 10 pm thickness for a feed mixture containing 5% benzene. Copolymer of acrylonitrile with styrene showed comparatively higher flux but lower selectivity. Ray et al. claimed that the selectivities obtained with these membranes were better than those reported in the literature. 

F.Q. Nie, Z.K. Xu, P. Ye, J. Wu, P. Seta, Acrylonitrile-based copolymer membranes containing reactive groups Effects of surface-immobilized poly(ethylene glycol)s on anti-fouling properties and blood compatibihty. Polymer, 45 (2004) 399-407. 

One of the prospective pathways for the synthesis of HCP involves copolymerization of neutral monomers with a basic ionogenic one. This procedure was used for synthesis of copolymers of acrylonitrile and dimethylaminoethyl methacrylate used for production of dialysis membranes67). Prior to use, the membranes were quater-nized with HC1 and subsequently treated with heparin. The reported high stability of the heparin-polymer complex (the loss of heparin on washing the polymer with distilled water for 70 hours was less than 1 %) does not obviously ensure that the HCP will perform properly when contacted with solutions of proteins and blood. 

This type of ion-exchange membrane is prepared by solving a polymer and a polyelectrolyte in one solvent. After that a film is casted and the solvent evaporated. For example a sulphonic interpolymer membrane can be prepared from a solution of linear polystyrene sulphonic acid, Dynel (a copolymer of acrylonitrile and vinylchloride) and dimethyl formamide (43). Other examples are given in (44,45,84, 169). 

W.Y. Chiang, C.C. Huang, Separation of liquid mixtures by using polymer membranes. Part IV. Water—alcohol separation by pervaporation through modified acrylonitrile poly(vinyl alcohol) copolymer, J. Appl. Polym. Sci. 48 (1993) 199-203. 

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