02259nas 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<p>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.</p>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-002146nas a2200217   4500008004100000022001400041245014900055210006900204260007300273300001200346490000800358520126700366653001901633653001901652653002201671653003501693100002101728700002601749700002201775856013101797       2016                        eng d  a0376-738800aPolybenzimidazole based polymeric ionic liquids possessing partial ionic character: effects of anion exchange on their gas permeation properties0 aPolybenzimidazole based polymeric ionic liquids possessing parti  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN  a282-2880 v4973 a<p>Polymeric ionic liquids (PILs) are emerging as promising membrane materials for CO2 separation. Present work is in continuation with our earlier efforts on evaluating gas permeation properties (especially, CO2) of film forming PILs based on polybenzimidazoles and efforts towards improving their permeability by structural tuning. This work specifically aims at evaluating effect of anion variation in chosen PILs possessing partial N-quaternization of imidazole moiety of PBI-Bul. Three anions (viz., Tf2N-, BF4- and Ac-) were chosen for the bromide exchange of two PILs, viz., [TBzPBI-Bul][Br](10) and [TBzPBI-Bul][Br](18), possessing degree of PEI N-quaternization (DQ) as 10 and 18%, respectively. Concurrent effects of variation in anion and DQ were analyzed in terms of physical and gas permeation properties of the resulting PILs. All of them possessed amorphous nature, adequate thermal stability ( &gt;= 250 degrees C) and solvent solubility, which are primary requisites towards their applicability as a membrane material. PILs possessing BF4- anion exhibited improved CO2 permeability coefficient as well as its permselectivity over CH4 and N-2, in comparison to their counterparts with other anions. (C) 2015 Elsevier B.V. All rights reserved.</p>10aAnion exchange10aGas separation10aPolybenzimidazole10aPolymeric ionic liquids (PILs)1 aRewar, Anita, S.1 aShaligram, Sayali, V.1 aKharul, Ulhas, K.  uhttp://library.ncl.res.in/content/polybenzimidazole-based-polymeric-ionic-liquids-possessing-partial-ionic-character-effects-1