@article { ISI:000263332200056,
	title = {Polyimides based on aromatic diisocyanates containing pendent flexible alkoxy chains and aromatic dianhydrides: synthesis, characterization, and liquid-crystal alignment properties},
	journal = {Journal of Applied Polymer Science},
	volume = {112},
	number = {1},
	year = {2009},
	month = {APR},
	pages = {461-472},
	publisher = {JOHN WILEY \& SONS INC},
	address = {111 RIVER ST, HOBOKEN, NJ 07030 USA},
	abstract = {<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{\textquoteright}-oxydiphthalic anhydride, 3,3{\textquoteright},4,4{\textquoteright}-(hexafluoroisopropylidene) diphthalic anhydride, and 3,3{\textquoteright},4,4{\textquoteright}-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{\textquoteright},4, 4{\textquoteright}-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{\textquoteright}-oxydiphthalic anhydride. (c) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 461-472, 2009</p>},
	keywords = {High performance polymers, polyimides, Thermal properties},
	issn = {0021-8995},
	doi = {10.1002/app.29388},
	author = {Sarkar, Anjana and Halhalli, Mahadeo R. and Kulkarni, Arun D. and Wadgaonkar, Prakash P.}
}
@article { ISI:000263629200030,
	title = {Synthesis and characterization of new polyimides containing pendent pentadecyl chains},
	journal = {European Polymer Journal},
	volume = {45},
	number = {2},
	year = {2009},
	month = {FEB},
	pages = {582-589},
	publisher = {PERGAMON-ELSEVIER SCIENCE LTD},
	address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND},
	abstract = {<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{\textquoteright},4,4{\textquoteright}-biphenyltetracarboxylic dianhydride (BPDA), 3,3{\textquoteright},4,4{\textquoteright}-benzophenone-tetracarboxylic dianhydride (BTDA), 4,4{\textquoteright}-oxydiphthalic anhydride (ODPA) and 4,4{\textquoteright}-(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>},
	keywords = {Cashew nut shell liquid, Glass transition temperature, Pendant pentadecyl chain, polyimides},
	issn = {0014-3057},
	doi = {10.1016/j.eurpolymj.2008.11.013},
	author = {Sadavarte, Nilakshi V. and Halhalli, Mahadeo R. and Avadhani, C. V. and Wadgaonkar, Prakash P.}
}
@article {44164,
	title = {Intrinsically microporous polyimides containing spirobisindane and phenazine units: synthesis, characterization and gas permeation properties},
	journal = {Journal of Polymer Science Part A - Polymer Chemistry},
	volume = {56},
	year = {2018},
	month = {APR },
	pages = {766-775},
	abstract = {A 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, 766-775},
	keywords = {Gas permeability, intrinsic microporosity, polyimides, spirobisindane},
	issn = {0887-624X},
	doi = {10.1002/pola.28950},
	author = {Shrimant, Bharat and Dangat, Yuvraj and Kharul, Ulhas K. and Wadgaonkar, Prakash P.}
}
