02266nas a2200277 4500008004100000022001400041245022700055210006900282260006700351300001400418490000800432520115200440653001901592653002601611653001401637653002401651653002301675100002401698700002301722700002201745700002501767700002201792700002401814700002201838856012801860 2011 eng d a0021-899500aPolybenzimidazoles based on 3,3 `-diaminobenzidine and aliphatic dicarboxylic acids: synthesis and evaluation of physicochemical properties toward their applicability as proton exchange and gas separation membrane material0 aPolybenzimidazoles based on 33 diaminobenzidine and aliphatic di a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcAPR a1090-10990 v1203 a

A series of aromatic-aliphatic polybenzimidazoles (PBIs) based on 3,3'-diaminobenzidine (DAB) and aliphatic dicarboxylic acid with incremental -CH2- groups were synthesized. Optimization of synthesis parameters and evaluation of physicochemical properties are requisite for PBI applicability as the proton exchange membrane (PEM) and gas separation membrane materials are reported. It was found that though all these PBIs exhibited high thermal, mechanical, and oxidative stability, effect of added flexibility on physical properties is not monotonous. Membranes were prepared by solution casting as well as phase-inversion method. The later types of membranes exhibited much higher H3PO4 content than its doping achieved in the solution casted membranes. These PBIs possess low hydrogen and helium permeability than that of conventional PBI. This low permeability, along with their excellent oxidative stability indicated that they can be promising PEM materials. Their CO2-sorption analysis revealed that PBI6 based on suberic acid possesses appreciable CO2 sorption. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 1090-1099, 2011

10aGas permeation10amechanical properties10amembranes10aoxidative stability10apolybenzimidazoles1 aBhavsar, Rupesh, S.1 aNahire, Sandip, B.1 aKale, Mrunali, S.1 aPatil, Shubhangi, G.1 aAher, Pradnya, P.1 aBhavsar, Ritesh, A.1 aKharul, Ulhas, K. uhttp://library.ncl.res.in/content/polybenzimidazoles-based-33-diaminobenzidine-and-aliphatic-dicarboxylic-acids-synthesis-002063nas a2200217 4500008004100000022001400041245012200055210006900177260007300246300001200319490000800331520120300339653001901542653003301561653002201594653002701616100002401643700002801667700002201695856012801717 2014 eng d a0376-738800aInvestigation of gas permeation properties of film forming polymeric ionic liquids (PILs) based on polybenzimidazoles0 aInvestigation of gas permeation properties of film forming polym aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV a494-5030 v4703 a

Polymeric ionic liquids (PILs) are emerging as new generation membrane materials for CO2 separation. Gas permeation properties of a recently developed PIL family based on three structurally different polybenzimidazoles (PBIs) possessing excellent film forming characteristics are reported. Effects of cationic backbone and anions on gas permeation properties of PILs using pure gases (He, H-2, N-2, CH4, and CO2) were examined at 20 atm upstream pressure and correlated with their physical properties. In comparison to the parent PBIs, PILs exhibited generally higher CO2 permeability, without largely affecting CO2 based selectivity. Some of these PILs exhibiting high PCO2/PCH4, selectivity and P-H2/P-CO2, approaching similar to 1 indicated dominance of CO2 sorption over diffusion. The CO2 sorption specificity of these PILs was distinctly observed based on their improved S-CO2/S-N2, S-CO2/S-CH4 and S-CO2/S-H2 selectivity than their parent PBIs. A large variation in permeation properties of PILs based on a common polycation but different anions indicated that anions play a crucial role on governing gas permeation properties of these PILs. (C) 2014 Elsevier B.V. All rights reserved

10aGas permeation10aMembranes for CO2 separation10aPolybenzimidazole10aPolymeric ionic liquid1 aBhavsar, Rupesh, S.1 aKumbharkar, Santosh, C.1 aKharul, Ulhas, K. uhttp://library.ncl.res.in/content/investigation-gas-permeation-properties-film-forming-polymeric-ionic-liquids-pils-based-002259nas a2200229 4500008004100000022001400041245015100055210006900206260007300275300001000348490000800358520136000366653002901726653001901755653002201774653002701796100002101823700002401844700001801868700002201886856012101908 2015 eng d a0376-738800aPolybenzimidazole based polymeric ionic liquids (PILs): effects of controlled degree of N-quaternization on physical and gas permeation properties0 aPolybenzimidazole based polymeric ionic liquids PILs effects of  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a19-270 v4813 a

Polymeric ionic liquids (PILs) are gaining increasing attention as potential membrane materials to be employed for CO2 separation. With a goal to improve gas permeability, this work presents a series of film forming PlLs obtained by controlled degree of N-quaternization (DQ) of PBI-BuI using a bulky 4-tertbutylbenzyl group. Concurrent effects of variation in ionic content and bulky group substitution were analyzed for physical and gas permeation properties of the resulting PILs. Attempted structural variations leading to simultaneous increments in ionic content and bulky groups offered amorphous polymers with acceptable thermal stability and non-monotonous chain packing density. Enhancement in pure gas permeability coupled with appreciable selectivity for various gas pairs was in accordance with the packing density variations in the series. Gas permeability showed maxima at DQ of just 13%. This conveyed that effects of bulky group substitution in retarding chain packing are overcome by attractive ionic interactions at much lower DQ in these PILs ionic interactions are thus more predominant in governing chain packing and gas permeation properties. These PILs possessed 3.3-20 times higher CO2 permeability in comparison to their parent PBI-BuI, without a significant loss in selectivity. (C) 2015 Elsevier B.V. All rights reserved.

10aDegree of quaternization10aGas permeation10aPolybenzimidazole10aPolymeric ionic liquid1 aRewar, Anita, S.1 aBhavsar, Rupesh, S.1 aSreekumar, K.1 aKharul, Ulhas, K. uhttp://library.ncl.res.in/content/polybenzimidazole-based-polymeric-ionic-liquids-pils-effects-controlled-degree-n-0