02694nas a2200217   4500008004100000022001400041245018500055210006900240260006800309300001200377490000800389520178900397653003002186653001502216653002302231100001902254700002602273700002302299700002802322856012602350       2009                        eng d  a0021-899500aPolyimides based on aromatic diisocyanates containing pendent flexible alkoxy chains and aromatic dianhydrides: synthesis, characterization, and liquid-crystal alignment properties0 aPolyimides based on aromatic diisocyanates containing pendent fl  a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcAPR  a461-4720 v1123 a<p>Four new aromatic diisocyanates containing pendent flexible alkoxy chains, namely, 5-butyloxy-1,3-phenylenediisocyanate, 5-octyloxy-1,3-phenylenediisocyanate, 5-dodecyloxy-1,3-phenylenediisocyanate, and 5-hexadecyloxy-1,3-phenylenediisocyanate, were synthesized by Curtius rearrangement of the corresponding 5-alkoxy-1,3-phenylene diacylazides. These diisocyanates were each polycondensed with three commercially available aromatic dianhydrides: 4,4'-oxydiphthalic anhydride, 3,3',4,4'-(hexafluoroisopropylidene) diphthalic anhydride, and 3,3',4,4'-benzophenonetetracarboxylic dianhydride-in benzonitrile in the presence of 1,4-dizabicyclo[2.2.2]octane as a catalyst to obtain a series of polyimides with inherent viscosities in the range 0.16-0.43 dL/g. Except for 3,3',4, 4'-benzophenonetetracarboxylic dianhydride based polyimides, all of the polyimides were found to be soluble in dichloromethane, m-cresol, 1-methyl-2-pyrrolidinone, tetra-chloroethane, and pyridine either at room temperature or on heating and could be cast into tough, flexible, transparent films from a solution in in-cresol or tetra chloroethane. X-ray diffractograms revealed that the polyimides with longer alkoxy chains had layered structures. The glass-transition temperature of the polyimides containing pendent flexible alkoxy chains were in the range 159-246 degrees C as measured by differential scanning calorimetry. The temperature for the 10% weight loss of the polyimides was in the range 410-460 degrees C in a nitrogen atmosphere, which indicated good thermal stability. A pretilt angle of 2.97 degrees was observed for the polyimide derived from 5-octyloxy-1,, 3-phenylenediisocyanate and 4,4'-oxydiphthalic anhydride. (c) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 461-472, 2009</p>10aHigh performance polymers10apolyimides10aThermal properties1 aSarkar, Anjana1 aHalhalli, Mahadeo, R.1 aKulkarni, Arun, D.1 aWadgaonkar, Prakash, P.  uhttp://library.ncl.res.in/content/polyimides-based-aromatic-diisocyanates-containing-pendent-flexible-alkoxy-chains-and-002231nas a2200229   4500008004100000022001400041245009000055210006900145260010600214300001200320490000700332520133100339653002801670653003301698653002901731653001501760100002801775700002601803700002101829700002801850856012301878       2009                        eng d  a0014-305700aSynthesis and characterization of new polyimides containing pendent pentadecyl chains0 aSynthesis and characterization of new polyimides containing pend  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcFEB  a582-5890 v453 a<p>A new unsymmetrical aromatic diamine, viz., 4-pentadecylbenzene-1,3-diamine was synthesized through a series of reaction steps starting from 3-pentadecylphenol. 4-Pentadecylbenzene-1,3-diamine was employed to synthesize a series of new polyimides by one-step polycondensation in m-cresol with four commercially available aromatic dianhydrides. viz., 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-benzophenone-tetracarboxylic dianhydride (BTDA), 4,4'-oxydiphthalic anhydride (ODPA) and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6-FDA). Inherent viscosities of resulting polyimides were in the range 0.33-0.67 dL/g and number average molecular weights were in the range 14,700-52,200 (GPC, polystyrene standard). Polyimides containing pendent pentadecyl chains were soluble in organic solvents such as chloroform, m-cresol, N,N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidinone (NMP), pyridine and nitrobenzene. Strong and flexible films of polyimides could be cast from their chloroform solutions. Polyimides exhibited glass transition temperature in the range 158-206 degrees C. The temperature at 10% wt. loss (T(10)). determined by TGA in nitrogen atmosphere, of polyimides was in the range 470-480 degrees C indicating good thermal stability. (C) 2008 Elsevier Ltd. All rights reserved.</p>10aCashew nut shell liquid10aGlass transition temperature10aPendant pentadecyl chain10apolyimides1 aSadavarte, Nilakshi, V.1 aHalhalli, Mahadeo, R.1 aAvadhani, C., V.1 aWadgaonkar, Prakash, P.  uhttp://library.ncl.res.in/content/synthesis-and-characterization-new-polyimides-containing-pendent-pentadecyl-chains-002537nas a2200229   4500008004100000022001400041245014600055210006900201260000900270300001200279490000700291520170500298653002102003653002802024653001502052653001902067100002102086700001902107700002202126700002802148856013102176       2018                        eng d  a0887-624X00aIntrinsically microporous polyimides containing spirobisindane and phenazine units: synthesis, characterization and gas permeation properties0 aIntrinsically microporous polyimides containing spirobisindane a  cAPR   a766-7750 v563 aA new diamine containing spirobisindane and phenazine units, namely, 3,3,3,3-tetramethyl-2,2,3,3-tetrahydro-1,1-spirobi[cyclopenta[b]phen azine]-7,7-diamine (TTSBIDA) was synthesized starting from commercially available 5,5,6,6-tetrahydroxy-3,3,3,3-tetramethyl-1,1-spirobisindane (TTSBI). TTSBI was oxidized to 3,3,3,3-tetramethyl-2,2,3,3-tetrahydro-1,1-spirobi[indene]-5,5,6,6-tet raone (TTSBIQ) which was subsequently condensed with 4-nitro-1,2-phenylenediamine to obtain 3,3,3,3-tetramethyl-7,7-dinitro-2,2,3,3-tetrahydro-1,1-spirobi[cyclope nta[b]phenazine] (TTSBIDN). TTSBIDN was converted into TTSBIDA by reduction of the nitro groups using hydrazine hydrate in the presence of Pd/C as the catalyst. A series of new polyimides of intrinsic microporosity (PIM-PIs) were synthesized by polycondensation of TTSBIDA with commercially available aromatic dianhydrides. PIM-PIs exhibited amorphous nature, high thermal stability (T-10&gt;480 degrees C) and intrinsic microporosity (BET surface area=59-289 m(2)/g). The gas permeation characteristics of films of selected PIM-PIs were evaluated and they exhibited appreciable gas permeability as well as high selectivity. The CO2 and O-2 permeability of PIM-PIs were in the range 185.4-39.2 and 30.6-6.2 Barrer, respectively. Notably, polyimide derived from TTSBIDA and 4,4-(hexafluoroisopropylidene)diphthalic anhydride (PIM-PI-6FDA) exhibited high CO2 and O-2 permeability of 185.4 and 30.6 Barrer with CO2/CH4 and O-2/N-2 selectivity of 43.1 and 5.1, respectively. The data of PIM-PI-6FDA for CO2/CH4 and O-2/N-2 gas pairs were located near Robeson upper bound. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 766-77510aGas permeability10aintrinsic microporosity10apolyimides10aspirobisindane1 aShrimant, Bharat1 aDangat, Yuvraj1 aKharul, Ulhas, K.1 aWadgaonkar, Prakash, P.  uhttp://library.ncl.res.in/content/intrinsically-microporous-polyimides-containing-spirobisindane-and-phenazine-units-synthesis