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1,2 -Bibenzimidazole oxidation

Chemical structures of (a) poly(ethersulfone) (b) polysulfone (c) sulfonated poly(ether ether ketone) (d) benzyl sulfonated poly(2,2 -/D-phenylene-5,5 -bibenzimidazole) (e) sulfonated polyiphenyl quinoxaline) (f) sulfonated poly(2,6-diphenyl-4-phenylene oxide). [Pg.51]

Aliphatic polybenzimidazoles were first synthesized by scientists in the 1950s. However, it was not until the 1960s that H. Vogel and C.S. Marvel first synthesized aromatic polybenzimidazoles and discovered that these unique, highly stable linear heterocyclic rigid-rod polymers exhibited exceptional thermal and oxidative stability [65]. Poly[2,2 -(m-phenylene)-5,5 -bibenzimidazole], PBI, was prepared by the condensation polymerization of... [Pg.17]

The Ru(bpy)2 -type centers have also been bridged by 2,2 -bis(2-pyridyl)-bibenzimidazole (A) and by l,2-bis(2-(2-pyridyl)benzimidazolyl) (B) ethane ligands (Fig. 5.23). Rapid intramolecular annihilation of the excited states are again observed. Similar multimetallic complexes of Ru(bpy)2 have been obtained using 2,2 -biimidazole (C) or 2,2 -bibenzimidazole (D) ligands to bridge the metal centers (Fig. 5.24). The excited states of these [Ru(bpy)2]2 complexes are strong reductants but weak oxidants. A [Ru(bpy)2 ]2 complex has been synthesized with... [Pg.204]

The need for HTPs or HTPBs is often for chemical (e.g., preventing of swelling or oxidation) and mechanical performance. For example, in the petroleum industry dual-layer hollow fiber membranes are used for separation of H2/CO2 and CO2/CH4 gases. These are prepared from solutions of 1 1 PIB/PI blend (e.g. poly[2,2 -(l,3-phenylene)-5,5 -bibenzimidazole] and poly[3,3 4,4 -benzophenone-icira-carboxylic-df-anhydride-co-5(6)-amino-l-(4 -amino-phenyl-l,3-/n-methyl-indane)]).i i The spun hollow fibers are coated by a solution of silicone rubber. The membranes had the desired microstructure. Membrane selectivity of 11.11 and 41.81 was obtained for H2/ CO2 and CO2/CH4, respectively. Furthermore, the new membranes showed good resistance toward COj-induced plasticization. Camacho-Zuniga et al. [Pg.73]


See other pages where 1,2 -Bibenzimidazole oxidation is mentioned: [Pg.993]    [Pg.30]    [Pg.30]    [Pg.230]    [Pg.197]    [Pg.254]    [Pg.254]    [Pg.255]    [Pg.262]   
See also in sourсe #XX -- [ Pg.39 , Pg.67 ]




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