02231nas a2200253 4500008004100000022001400041245011000055210006900165260006800234300001400302490000800316520130500324653001901629653001401648653001501662653001601677653003301693100002701726700002501753700002201778700002401800700002601824856012701850 2008 eng d a0021-899500aSynthesis, characterization, and gas permeability of aromatic polyimides containing pendant phenoxy group0 aSynthesis characterization and gas permeability of aromatic poly a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcJUN a3881-38890 v1083 a

A diamine containing a pendant phenoxy group, 1-phenoxy-2,4-diaminobenzene, was synthesized and condensed with different aromatic dianhydrides [4,4'-oxydiphthalic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 3,3',4,4-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracorboxylic dianhydride, and pyromellitic dianhydride] by one-step synthesis at a high temperature in m-cresol to obtain polyimides in high yields. Most of the polyimides exhibited good solvent solubility and could be readily dissolved in chloroform, sym-tetrachloroethane, N,N-dimethylformamide, NN-dimethylacetamide, and nitrobenzene. Their inherent viscosities were in the range of 0.33-1.16 dL/g. Wide-angle X-ray spectra revealed that these polymers were amorphous in nature. All these polyimides were thermally stable, having initial decomposition temperatures above 500 degrees C and glass-transition temperatures in the range of 248-281 degrees C. The gas permeability of 4,4'-oxydiphthalic dianhydride and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride based polyimides was investigated with pure gases: He, H-2, O-2, Ar, N-2, CH4, and CO2. A polyimide containing a -C(CF3)(2)- linkage showed a good combination of permeability and selectivity. (C) 2008 Wiley Periodicals, Inc.

10aGas permeation10amembranes10apolyimides10aselectivity10astructure-property relations1 aKothawade, Sandeep, S.1 aKulkarni, Mahesh, P.1 aKharul, Ulhas, K.1 aPatil, Anandrao, S.1 aVernekar, Subhash, P. uhttp://library.ncl.res.in/content/synthesis-characterization-and-gas-permeability-aromatic-polyimides-containing-pendant-002266nas 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-001446nas a2200241 4500008004100000022001400041245013900055210006900194260007500263300001400338490000700352520051100359653003200870653001900902653001400921653002600935653002000961100002300981700002701004700002001031700002201051856013101073 2016 eng d a0947-653900aChemically stable covalent organic framework (COF)-polybenzimidazole hybrid membranes: enhanced gas separation through pore modulation0 aChemically stable covalent organic framework COFpolybenzimidazol aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcMAR a4695-46990 v223 a

Highly flexible, TpPa-1@PBI-BuI and TpBD@PBI-BuI hybrid membranes based on chemically stable covalent organic frameworks (COFs) could be obtained with the polymer. The loading obtained was substantially higher (50%) than generally observed with MOFs. These hybrid membranes show an exciting enhancement in permeability (about sevenfold) with appreciable separation factors for CO2/N-2 and CO2/CH4. Further, we found that with COF pore modulation, the gas permeability can be systematically enhanced.

10acovalent organic frameworks10aGas separation10amembranes10amicroporous materials10apore modulation1 aBiswal, Bishnu, P.1 aChaudhari, Harshal, D.1 aBanerjee, Rahul1 aKharul, Ulhas, K. uhttp://library.ncl.res.in/content/chemically-stable-covalent-organic-framework-cof-polybenzimidazole-hybrid-membranes-enhanced01965nas a2200217 4500008004100000022001400041245014600055210006900201260009900270300001000369490000700379520107700386653001901463653001401482653002801496100002601524700002101550700002801571700002201599856012601621 2016 eng d a0032-386100aIncorporation of rigid polyaromatic groups in polybenzimidazole-based polymeric ionic liquids: assertive effects on gas permeation properties0 aIncorporation of rigid polyaromatic groups in polybenzimidazoleb aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcJUN a30-360 v933 a

Polymeric ionic liquids (PILs) have emerged as promising membrane materials for CO2 separation. The present work is aimed at investigating the effects of incorporation of rigid polyaromatic hydrocarbons, viz., pyrene and anthracene, in polybenzimidazole-based PILs. The effects of substituent and anion variation on the gas permeation properties of PILs using pure gases were examined at 20 atm upstream pressure. The results were correlated with physical properties of PILs. The pyrene substituted PIL exhibited similar to 10 fold increase in CO2 permeability as compared to its precursor polymer PBI-BuI. The combination of a CO2 specific anion and bulky group substitution offered higher CO2 permeability as well as appreciable permselectivity than their structural analogue that was devoid of IL functionality. The permeation properties of present PILs were superior to those of conventional glassy polymers such as polysulfone, matrimid and polycarbonate which are widely studied for their gas permeation properties. (C) 2016 Elsevier Ltd. All rights reserved.

10aGas permeation10amembranes10aPolymeric ionic liquids1 aShaligram, Sayali, V.1 aRewar, Anita, S.1 aWadgaonkar, Prakash, P.1 aKharul, Ulhas, K. uhttp://library.ncl.res.in/content/incorporation-rigid-polyaromatic-groups-polybenzimidazole-based-polymeric-ionic-liquids02570nas a2200241 4500008004100000022001400041245012400055210006900179260000900248300001000257490000700267520172200274653001501996653001902011653002802030653001402058653003302072100002102105700002602126700002202152700002802174856012602202 2018 eng d a0887-624X00aSynthesis, characterization, and gas permeation properties of adamantane-containing polymers of intrinsic microporosity0 aSynthesis characterization and gas permeation properties of adam cJAN  a16-240 v563 a

A new bis(catechol) monomer, namely, 4,4-((1r,3r)-adamantane-2,2-diyl)bis(benzene-1,2diol) (THADM) was synthesized by condensation of 2-adamantanone with veratrole followed by demethylation of the formed (1r,3r)-2,2-bis(3,4 dimethoxyphenyl)adamantane. Polycondensation of THADM and various compositions of THADM and 5,5,6,6-tetrahydroxy-3,3,3,3-tetramethylspirobisindane was performed with 2,3,5,6-tetrafluoroterephthalonitrile (TFTPN) to obtain the homopolymer and copolymers. These polymers demonstrated good solubility in common organic solvents such as dichloromethane, chloroform, and tetrahydrofuran and could be cast into tough films from their chloroform solutions. GPC analysis revealed that number average molecular weights of polymers were in the range 48,100-61,700 gmol(-1), suggesting the formation of reasonably high molecular weight polymers. They possessed intrinsic microporosity with Brunauer-Emmett-Teller (BET) surface area in the range 703-741 m(2)g(-1). Thermogravimetric analysis of polymers indicated that 10% weight loss temperature was in the range 513-518 degrees C demonstrating their excellent thermal stability. THADM-based polymer of intrinsic microporosity (PIM) showed P(CO2)=1080, P(O-2)=232 and appreciable selectivity [(CO2/CH4)=22.6, (CO2/N-2)=26.7, and (O-2/N-2)= 5.7]. The gas permeability measurements revealed that with increase in the content of adamantane units in PIMs, selectivity increased and permeability decreased, following the trade-off relationship. The gas separation properties of PIMs containing adamantane units were located close to 2008 Robeson upper bound for gas pairs such as CO2/CH4, CO2/N-2, H-2/N-2, and O-2/N-2. (c) 2017 Wiley Periodicals, Inc.

10aadamantane10aGas permeation10aintrinsic microporosity10amembranes10astructure-property relations1 aShrimant, Bharat1 aShaligram, Sayali, V.1 aKharul, Ulhas, K.1 aWadgaonkar, Prakash, P. uhttp://library.ncl.res.in/content/synthesis-characterization-and-gas-permeation-properties-adamantane-containing-polymers