Poly 4 -vinyl-imidazole

The lower the initiator concentration the higher the molecular weight of polymer formed. Moreover, the effect of the ratio template/monomer concentration is more pronounced for low initiator concentration. In addition, it was found that tacticity of the template does not influence the suppression of degradative addition nor the tacticity of the poly(vinyl imidazole) obtained by the template process. 

Significant research has been directed toward the use of polyelectrolyte complexes as blood compatible materials. Several investigators found that water-insoluble polyelectrolyte complexes can suppress blood coagulation [487-490]. Davison and coworkers reviewed and studied the biological properties of water-soluble polyelectrolyte complexes [491] between quatemized poly(vinyl imidazole) or polyvinyl pyridine) and excess sulfonated dextran or poly(methacrylic acid). By forming complexes with a stoichiometric excess of anionic charge, a more compact conformation with anionic character was obtained. 

The first example for Method 2 was reported by Nishide and co-workers, who polymerised a metal complex of 1-vinylimidazole with l-vinyl-2-pyrollidone and divinylbenzene [8]. The metal-vinylimidazole complex was copolymerised, cross-linked with l-vinyl-2-pyrollidone by y-ray irradiation and the template metal ion was removed by treating the polymer complex with an acid. These poly(vinyl-imidazole) (PVI) resins adsorbed metal ions more effectively than the PVI resin prepared without the template. The number of adsorption sites and the stability constant of the Ni(II) complex were larger for the PVI resin prepared with the Ni(II) template, as seen by the smaller dissociation rate constant of Ni(II) from the resin. 

Recently, Schuhmann et al. reported ethanol biosensors by entrapping quinohemoprotein alcohol dehydrogenase and Os-complex-modified poly(vinyl imidazole) during the electrochemically induced deposition of the poly(acrylate)-based resin [80]. The sensor exhibited its efficiency and also sufficient stability for practical applications. Author claims that the reported sensor preparation process is simple, easy to control, oxygen insensitive and can be applicable to other enzyme sensors. 

Bohmer, M.R. et al., Adsorption of partially quarternized poly (vinyl imidazoles) onto SiO2 and YjO, Colloids Surf. A, 99, 53,1995. 

As discussed before, the borderline between polysoaps and polyelectrolytes or thickeners is determined by the hydrophilic-hydrophobic balance HLB, as well as by the length and the density of the hydrophobic tails chosen. The longer they are, the lower is the content of hydrophobic tails - the Critical Alkyl Group Content CAC [52, 75] - needed in order to produce polysoap behaviour (cf. Sect. 2.3.2). For poly(2-vinylpyridine) and poly(4-vinylpyridine), about 20% of derivatization with octyl tails and about 10% of derivatization with dodecyl tails are needed as a minimum to obtain the characteristic low viscosities [49, 52, 75, 133, 141, 317] (Fig. 17). Comparable CAC values are obtained for derivatized poly(vinyl-imidazol)s [140] and for poly(allylamine)s [152]. Similarly in anionic copolymers of poly(sodium 2-acrylamido-2-... 

High mediator loading can be achieved by covalent binding of Os-complexes to a poly(vinyl pyridine) [130-137], a poly(vinyl imidazole) [138, 139], a... 

The thermooxidative degradation and SiOx film formation of poly(vinyl imidazole-co-vinyl trimethoxysilane) on copper was investigated. Thermal degradation of the copolymer was catalysed by copper in the film and at the substrate surface. Copper in the copolymer film contributed to the formation of a copper-containing SiOx film during thermal degradation. Copper oxides in the film interacted with the SiOx film to form a copper-rich phase near the film defects and cracks (142). 

Saponification of type (III) esters with poly(vinyl imidazole) (IV) as catalyst proceeds about 1000 times faster than saponification with imidazole (V) as catalyst. In addition, the polymer-catalyzed reaction is autocatalytic. The saponification rate increases with the length of the acyl residue (by a factor of 25 from w = 1 to w = 17). Obviously, increased methylene chain length leads to increasing intramolecular association of the polymer, which is acylated in an intermediate step of the reaction ... 

Figure 9.8 lists the representative examples of pH-responsive polybases. Poly(A,A -dimethyl aminoethyl methacrylate) (PDMAEMA) (Fig. 9.8a) and poly(A,A-diethyl aminoethyl methacrylate) (PDEAEMA) (Fig. 9.8b) have pH-responsive amine groups in their side chains, which can gain protons under acidic conditions and release them under basic conditions. Poly(4-vinylpyridine) (PVP) shows pH sensitivity (Fig. 9.8c) owing to the pyridine group [8, 53]. Poly(vinyl imidazole) (PVI) is another pH-responsive polymer consisting of an imidazole group (Fig. 9.8d) [54]. 

FIGURE 9.8 Typical pH-responsive polybases (a) poly(M,Al -dimethyl aminoethyl methacrylate) (PDMAEMA) (b) poly(A,A -diethyl aminoethyl methacrylate) (PDEAEMA) (c) poly(4-vinylpyridine) (PVP) (d) poly(vinyl imidazole) (PVI). 

C. C. Gryte and H. P. Gregor, Interpolymer Ultrafiltration Membranes Prepared from Poly(vinylidene Fluoride) and Poly(l-vinyl-3-methylimidazolium Iodide, J. Macromol. Sci.-Phys. B15(2), 183 (1978). Poly(vinyl imidazole)/poly(vinylidene fluoride)/epoxy semi-IPN. Ion exchange membrane. 

So far, it has been reported that redox polymers, such as polysiloxane or polyarrylamide on which ferrocene is introduced as a side chain, are effective mediators [15-25]. Other effective mediators include poly(vinyl pyridine) or poly(vinyl imidazole) on which osmium complex is introduced in the side chain. However, the structure-mediator fimction correlation has been poorly understood. Here, the glucose sensor was used as an example of enzyme sensors, and as shown in Table 1, sensors using enzymes other than glucose oxidase have also been actively studied. It is now possible to detect electrochemically materials in the body using an electrode with an enzyme and a polymer gel. 

Poly(vinyl imidazole) Poly(vinyl pyrrolidone)... 

Imidazole units have been substituted on poly(vinyl alcohol) chains to the extent of 19-51% as shown in Equation 14 (54). This reaction was run 1-5 days as a 1% solution in DMF at 85°C. Using the sequence of reactions outlined in Equation 15, 6-methylthio-purine units have been placed on the poly(vinyl alcohol) backbone (55). These polymers might be useful in treating cancer or leukemia since the parent compound, 6-mercaptopurine, is used in this way. 

Tsuchida et al. [33], synthesized Poly(l-vinyl and l-vinyl-2-methyl-imidazole) bound heme (iron-porphyrin) complexes as models for mimicking natural oxygen carriers such as hemoglobin. The reaction between AIBN polymerized poly(l-vinyl)imidazole, or poly(l-vinyl-2-methylimidazole) and Fe(III) protoporphyrin IX diethyl ester in DMF and small amount of Na2S204 yields the Fe(III) complex (Fig. 15),... 

Finally, a noteworthy procedure (78MI11105) for attaching the imidazole heterocycle to poly(vinyl alcohol) (180) has been reported, but has not yet been utilized in any practical sense. The procedure (Scheme 96) involves reaction of the polymer with 4-chloromethyl-imidazolium chloride (201) in DMF solution DMF is apparently a sufficiently strong base to effect the attachment. 

The hydrolysis of copolymers containing vinyl imidazole (Vim) as the third component, poly(MAOT-co-AA-co-VIm) (No. 15), poly(AOT-co-AA-co-VIm) (No. 13), and poly(MAOA-co-AA-co-VIm) (No. 17), is shown in Fig. 3. These copoly-... 

The increase of hydrophobicity in the substrate shows the increase in the binding. The hydrolysis of 3-nitro-4-acyloxy benzoic acid (8) by poly(4(5)-vinyl-imidazole) (II) is much influenced by the acyl chain length in the substrate (24,25, 56, 72). The increase of the acyl chain length makes the binding increase and the deacylation decrease. In the hydrolysis of the substrate having the longer acyl chain, a micelle effect should be considered. The hydrolysis is much influenced by the micelle formation. 

Both poly(l-butyl-5-vinylimidazole), poly(lB-5IM), and poly(l-methyl-5-vinyl-imidazole), poly(lM-5IM), have no quatemizable nitrogen, so that the coulombic interaction with the substrate is not necessarily to be considered. Using these polymers, hydrolyses of several 3-nitro-4-acyloxy benzoic acid having various acyl chain length (8) (n = 0,5,10,16) have been made (55). The apparent rates of hydrolyses are tabulated in Table 7. 

Poly(N-vinyl-imidazole) (PVI) and Poly(4(5)-vinyl-imidazole) (P4VI). . 62... 

Poly[4(5)vinyl-imidazole] can be obtained by radical polymerization of the corresponding monomer, in turn obtained by decarboxylation of transurocanic acid M> or by pyrolysis of 4 3-acetoxy)ethylimidazole 35). 

Cross-linked poly(N-vinyl-imidazole) was obtained by reaction of poly(N-vinyl-imidazole) with 1,4 dibromobutane37>. 

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