Vinylimidazole-methacrylic acid

A set of papers was devoted to the polymerization of N- vinylimidazole in poly(methacrylic acid) matrix. Vinylimidazole is soluble in water and polymerization was carried out in aqueous system using 2,2 -azobis(2-amidopropane)2HCl as initiator ... 

Chain transfer to the monomer is discussed by Van den Grampel in connection with polymerization of N-vinylimidazole in the presence of poly(methacrylic acid). Degradative addition by a radical at the 2-position of the imidazole ring can be illustrated by the reaction ... 

In these equations I is the initiator and I- is the radical intermediate, M is a vinyl monomer, I—M- is an initial monomer radical, I—MnM- is a propagating polymer radical, and and M7 are polymer end groups that result from termination by disproportionation. Common vinyl monomers that can be homo-or copolymerized by radical initiation include ethylene, butadiene, styrene, vinyl chloride, vinyl acetate, acrylic and methacrylic acid esters, acrylonitrile, IV-vinylimidazole, IV-vinyl-2-pyrrolidinone, and others (2). 

Thus one might expect flexible, water-soluble synthetic polymers with suitable side chains to show affinities for small molecules. We have examined, over several decades, the binding ability of poly(vinylpyrrolidone), polyvinylpyridine, polylysine, polyacrylamide, poly(isopropylacrylamide), poly(vinylimidazole), poly(vinylmethyloxazolidi-none), poly(vinylmethyloxazolidinone-vinylimidazole), poly(vinylpyrrolidone-vinyli-midazole), poly(vinylpyrrolidone-vinyl alcohol), poly(vinylpyrrolidone-maleic anhydride), poly(vinylmethyloxazolidinone-maleic anhydride), and poly(2-methylami-noethyl methylacrylate-methacrylic acid). Other investigators have studied similar synthetic polymers [5-12], In our experience no water-soluble polymer binds small molecules with an avidity comparable to serum albumin. 

It has been attempted to perform template polymer syntheses without using biological sources. Concepts focus on the formation of a complex between monomer molecules and a present macromolecule [4,480], This way the monomer will get preorganized and the polymerization is supposed to follow a zip mechanism controlled by the length and the configuration of the template polymer, offering replication of the molecular weight and control of the stereo structure. Polymerization of acrylic acid in the presence of poly(ethyleneimine), N-vinylimidazole/ poly(methacrylic acid) or acrylonitrile with poly(vinylacetate) have been described [469,470,471,472,473]. Recently the preparation of solid polyelectrolyte complexes from chitosan and sodium-styrenesulfonate has been reported [481]. 

Most importantly for a successful imprinting by an ion template is the formation of a well-defined polymerisable metal complex in solution prior to polymerisation. Hence metal specific ligands are of particular interest and attempts to improve selectivity have been focused on them. Vinylimidazoles [127], diesters of vinylphosphonic acid [128,129], 4-vinyl-2,2 -bipyridines [130, 131] and methacrylic acid with vinylpyridine [132] are the most intensely studied ligands [133]. 

Note PAC, poly(acrylic acid) PVAI, poly(vinyl alcohol) PMAAc, poly(methacrylic acid) PVIA, poly(A-vinylimidazol) PVPy, poly(4-vinylpyridine). coordination number (CN) = 4. 

Compatibilized blends of ethylene-methacrylic acid copolymer and PS were prepared by Kim et al. (1998) through addition of S-co-4-vinylpyridine. Similarly, blends of poly(isobutyl methacrylate) were compatibilized with poly(styrene-co-methacrylic acid) using poly(isobutyl methacrylate-co-2-(A, A -dimethylamino) ethyl methacrylate) or poly(isobutyl methacrylate-co-4-vinylpyridine) (Habi and Djadoun 1999). Turcsayii (1995) has reported compatibilized blends of PE-g-(N-vinylimidazole) with acrylic acid-modified PP. 

The pure bulk-phase behavior was studied on blends consisting of poly(acryhc acidj/hydroxypropyl cellulose [44], poly(2-vinylpyridine)/end-sufonic acid poly(styrene) [45], and poly(acryHc acid)/poly(N,N-dimethyl-acrylamide) [46]. Goh et al. [47,48] and others [49] have studied an interesting example of [60]fullerenated poly(2-hydroxyethyl methacrylate) with poly(l-vinylimidazole) or poly(4-vinylpyridine) or poly(styrene-co-4-... 

The same technique can be used to dye a material that is otherwise difficult to dye. An ethylene-propylene copolymer rubber was reacted first with maleic anhydride, then with an aromatic amine dye in an extruder to produce a dyed rubber.81 Dye sites can also be inserted into polyolefins by grafting them with dimethylaminoethyl methacrylate, using azo or peroxide catalysts in an extruder.82 jV-Vinylimidazole has been grafted to polyethylene in an extruder with the help of dicumylperoxide.83 The product was mixed with an acrylic acid-modified polypropylene and used to compatibilize polyethylene and polypropylene. This could be helpful in the recycling of mixed polyolefins from municipal solid waste. Recycling of cross-linked (thermoset) polymers is more of a problem because they cannot be remelted in an extruder. However, they can be if... 

Among the most frequently used monomers we can mention carboxylic acids (e.g. acrylic, methacrylic and vinyl benzoic acids), sulfonic acids and heterocyclic bases (e.g. vinylpyridines, vinylimidazoles). 

The acid-base Nafion composite membranes include blends of Nafion with polypyrrole (PPy) [98-104], polybenzimidazole (PBI) [105-107], poly (propyleneoxide) (PPO) [108, 109], polyfurfuryl alcohol (PFA) [110], poly(vinyl alcohol) (PVA) [111-115], sulfonated phenol-formaldehyde (sPF) [116], polyvinylidene fluoride (PVdF) [117-122], poly(p-phenylene vinylene) (PPV) [123], poly(vinyl pyrrolidone) (PVP) [124] polyanifine (PANI) [125-128], polyethylene (PE) [129], poly(ethylene-terephtalate) [130], sulfated p-cyclodextrin (sCD) [131], sulfonated poly(ether ether ketone) (sPEEK) [132-135], sulfonated poly(aryl ether ketone) (sPAEK) [136], poly(arylene ether sulfone) (PAES) [137], poly(vinylimidazole) (PVl) [138], poly(vinyl pyridine) (PVPy) [139], poly (tetrafluoroethylene) (PTFE) [140-142], poly(fluorinated ethylene-propylene) [143], sulfonated polyhedral oligomeric silsesquioxane (sPOSS) [144], poly (3,4-ethylenedioxythiophene) (PEDT) [145, 146], polyrotaxanes (PR) [147], purple membrane [148], sulfonated polystyrene (PSSA) [149, 150], polystyrene-b-poly(ethylene-ran-butylene)-bpolystyrene (SEES) [151], poly(2-acrylamido-2-methyl-l-propanesulphonic acid-co-l,6-hexanediol propoxylate diacrylate-co-ethyl methacrylate) (AMPS) [152], and chitosan [31]. A binary PVA/chitosan [153] and a ternary Nafion composite with PVA, polyimide (PI) and 8-trimethoxy silylpropyl glycerin ether-1,3,6-pyrenetrisulfonic acid (TSPS) has also been reported [154]. 

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