Imidazole polybenzimidazole

Polymer blends leading to high-end polymers, e.g. from sulfonated polymers (sPEEK - sulfonated polyether-etherketone, sPPSU - sulfonated polyphenyl-sulfone) combined with alkaline components (amine, imidazole, polybenzimidazole) The combination results in ionic cross-linked phases. Commercially available polymers can be modified by different sulfonation reagents. Another possibility is to combine different monomers based on block co-polymers. The conductivity can be controlled by the number of S03H groups due to the dependence of the water uptake from the number of groups ([23] and references cited therein). 

A. Schechter and R.F. Savinell. Imidazole and 1-methyl imidazole in phosphoric acid doped polybenzimidazole, electrolyte for fuel cells. Solid State Ionics 147, 181-187 2002. 

Several years ago, encouraged by the proven intermediacy of polyimidazolines in Gray s imidazole polymer synthesis we set out to demonstrate experimentally an analogous intermediary stage in the polycondensation of Scheme 13 and develop a preparative approach that would enable us to isolate soluble polyimidazoline intermediates. Clearly, if such polymeric imidazolines could be isolated and their further smc th conversion to polybenzimidazoles be accomplished, the door would be opened for the development of two-stage processing techniques involving prepolymer-type materials. Initial... 

The importance of the anionic imidazole species is mcwe apparent when polybenzimidazole 2 (pKai = 3.5, pKg2 = 12.2) is employed as catalyst (50). The value for polyvinylbenzimidazole-catalyzed solvolysis of PNPA 3 increased with increasing pH and was about four times greater than that for benzimidazole-catalyzed solvolysis over the pH range of 4 to 10. Arim for the polymer-catalyzed solvolysis of NABS increased similarly with increasing pH, whereas that for benzimid-... 

Chuang SW, Hsu SLC, Yang ML (2008) Preparation and characterization of fluOTine-containing polybenzimidazole/imidazole hybrid membranes for proton exchange membrane fuel cells. Eur Polym J 44 2202-2206... 

Miller M, Sherrington D. Alkene epoxida-tions catalyzed by Mo(VI) supported on imidazole-containing polymers II. Recycling of polybenzimidazole-supported MO(VI) in the epoxidation of cyclohexene. J Catal 1995 152(2) 377-83. 

Kerres et al., among others, developed the acid-base blend membranes from sulfonated polymers and aminated or other basic polymers [98] and concluded that the protonation of the basic groups is incomplete if the base is too weak [99]. Very recently, Frutsaert et al. [70] synthesized novel polymers for the development of high temperature PEMFC membranes comprising a blend of s-PEEK and a fluorinated copolymer bearing imidazole functions as pendant groups. The extensive work on intermediate temperature fuel cell membranes are well reviewed in Chap. 4 of this book including polybenzimidazole as the basic component and sulfonated and phosphonated ionomers of either nonfluorinated or partially fluorinated backbones as the acidic component. 

High working temperatures benefit PEMFC performances because of faster electrode kinetics, higher CO tolerance and the possibility to use the residual heat for energy cogeneration [5, 6]. Among the polybenzimidazole derivatives, the most widely studied are the commercially available poly[2,2 -(m-phenylene)-5,5 -bibenzimidazole] with the acronyms w-PBI and poly(2,5-benzimidazole), AB-PBI (see Fig. 8.1). The polymers contain a basic imidazole functionality that allows the uptake of the acid protic electrolyte, which is responsible, and required, for the proton... 

Structural studies of polymer surfaces materials that have been studied include polymethyl methacrylate (PMMA) [22], PMMA-polypyrrole composites [23], poly(chloromethyl styrene) bound 1,4,8,11 tetrazacrylotetra decane poly(chloromethyl styrene) bound theonyl trifluoroacetone [24], polydimethyl siloxane-polyamide copolymers [25], PS [26], ion-implanted PE [27], monoazido-terminated polyethylene oxide [28], polyurethanes [29], polyaniline [30], fluorinated polymer films [31], poly(o-toluidine) [32], polyetherimide and polybenzimidazole [33], polyfullerene palladium [34], imidazole-containing imidazolylethyl maleamic acid - octadecyl vinyl ether copolymer [35], polyphenylene vinylene ether [36], thiphene oligomers [37], fluorinated styrene-isoprene derivative of a methyl methacrylate-hydroxyethyl methacrylate copolymer [38], polythiophene [39], dibromoalkane-hexafluorisopropylidene diphenol and bisphenol A [40], and geopolymers [41],... 

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