@article { ISI:000251631200005, title = {Effect of substituent polarity, bulk, and substitution site toward enhancing gas permeation in dibromohexafluorobisphenol-A based polyarylates}, journal = {Journal of Polymer Science Part B-Polymer Physics}, volume = {45}, number = {23}, year = {2007}, month = {DEC}, pages = {3156-3168}, publisher = {JOHN WILEY \& SONS INC}, type = {Article}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

The gas permeation properties of polyarylates were tuned by varying nature and site of substituents present on both of its monomers, viz., bisphenol and dicarboxylic acid. The phenyl rings of hexafluorobisphenol-A were substituted in asymmetric manner by polar bromine to obtain dibromohexafluorobisphenol-A. This bisphenol was polymerized with equimolar mixture of iso- and terephthalic acid (base case), bromo- and nitroterephthalic acid (polar group substituted acids), 4,4{\textquoteright}-hexafluoroisopropylidene bis(benzoic acid), and t-butyl isophthalic acid (bulky group containing acids). Physical properties and gas permeation properties of these polyarylates were investigated to assess combined effects of asymmetric nature of bisphenol substitution, polar nature of substituent bromine, hexafluoroisopropylidene group present at the bridge position of bisphenol, and substituent present on the acid moiety. The combination of these substituent types led these polyarylates to lie near Robeson upper bound. The gas sorption analysis and estimation of diffusivity in these polyarylates shed a light on observed variations in gas permeation properties by attempted structural variations. (c) 2007 Wiley Periodicals, Inc.

}, keywords = {asymmetric substitution, Diffusion, Gas permeation, gas sorption, polyarylates, selectivity, structure-property relations}, issn = {0887-6266}, doi = {10.1002/polb.21314}, author = {Ishole, Yogesh S. and Karadkar, Prasad R. and Kharul, Ulhas K.} } @article { ISI:000255339200058, title = {Synthesis, characterization, and gas permeability of aromatic polyimides containing pendant phenoxy group}, journal = {Journal of Applied Polymer Science}, volume = {108}, number = {6}, year = {2008}, month = {JUN}, pages = {3881-3889}, publisher = {JOHN WILEY \& SONS INC}, type = {Article}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

A diamine containing a pendant phenoxy group, 1-phenoxy-2,4-diaminobenzene, was synthesized and condensed with different aromatic dianhydrides [4,4{\textquoteright}-oxydiphthalic dianhydride, 4,4{\textquoteright}-(hexafluoroisopropylidene)diphthalic anhydride, 3,3{\textquoteright},4,4-benzophenone tetracarboxylic dianhydride, 3,3{\textquoteright},4,4{\textquoteright}-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{\textquoteright}-oxydiphthalic dianhydride and 4,4{\textquoteright}-(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.

}, keywords = {Gas permeation, membranes, polyimides, selectivity, structure-property relations}, issn = {0021-8995}, doi = {10.1002/app.28074}, author = {Kothawade, Sandeep S. and Kulkarni, Mahesh P. and Kharul, Ulhas K. and Patil, Anandrao S. and Vernekar, Subhash P.} } @article { ISI:000264247300034, title = {Reactive extrusion of poly(L-Lactic Acid) with glycidol}, journal = {Journal of Applied Polymer Science}, volume = {112}, number = {3}, year = {2009}, month = {MAY}, pages = {1391-1398}, publisher = {JOHN WILEY \& SONS INC}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

Glycidol modified polylactic acid (PLLA) polymers have been prepared by reactive extrusion. Influences of residence time and the concentration of glycidol on the extent of reaction with different weight average molecular weight (45,000, 65,000, and 100,000) PLLA{\textquoteright}s were studied. Structure-property relationship has been established by measuring molecular, mesoscopic, and macroscopic properties. Under reactive extrusion conditions glycidol reacted with the end groups of PLLA to initiate chain extension. Low-molecular weight PLLA reacted with glycidol faster than the medium molecular weight PLLA, whereas high-molecular weight PLLA did not show significant reactions. The glass transition temperature, melting temperature, crystallization temperature, and heat of fusion were measured for unmodified and modified PLLA{\textquoteright}s. Chain extended PLLA had higher T(g) and T(m) than the unmodified samples. Time sweep rheological experiments were performed to test the melt stability of PLLA. Chain extended PLLA{\textquoteright}s were found to retain viscoelastic properties for much longer time than the unreacted samples. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 1391-1398, 2009

}, keywords = {biodegradable, reactive extrusion, Rheology, structure-property relations, Thermal properties}, issn = {0021-8995}, doi = {10.1002/app.29581}, author = {Deenadayalan, E. and Lele, Ashish K. and Balasubramanian, M.} } @article { ISI:000263163200021, title = {Synthesis and self-organization properties of copolyurethanes based on perylenediimide and naphthalenediimide units}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {47}, number = {4}, year = {2009}, month = {FEB}, pages = {1224-1235}, publisher = {JOHN WILEY \& SONS INC}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

A series of perylene and naphthalene diimide-containing random copolyurethanes with different ratios of perylene/naphthalene diimide content was synthesized and characterized. Copolymerization improved the solubility of these rigid aromatic diimides, and the copolymers were soluble in common organic solvents like chloroform, tetrahydrofuran, and so forth. The absorption spectra of perylene-based copolymers showed a red-shifted peak at a wavelength of 557 nm corresponding to J-type aggregates. For naphthalene copolymers, the quenching of fluorescence at higher naphthalene incorporation suggested the presence of aggregates because of the extensive pi-pi stacking of the aromatic core. FTIR spectroscopic analysis showed that the hydrogen bonding tendency of the polymer decreased with increase in perylene/naphthalene incorporation. The fluorescence spectra of the perylene polymers were exactly a mirror image of the absorption spectra. The fluorescence spectra of the naphthalene polymers at higher naphthalene incorporation showed a red-shifted excimer like emission peak, which was assigned as static excimers based on their excitation spectra. These polymers could exhibit two types of secondary interaction modes, namely, hydrogen bonding (via urethane linkage) and pi-stacking (via aromatic perylene or naphthalene units) thus highlighting the importance of polymer design in inducing self-organization at both low and high incorporation of the rigid bisimide moieties. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polyrn Chem 47: 1224-1235, 2009

}, keywords = {fluorescence, hydrogen bonding, naphthalene diimide polymers, polyurethane copolymer, self-organization, structure-property relations}, issn = {0887-624X}, doi = {10.1002/pola.23233}, author = {Jancy, B. and Asha, S. K.} } @article { ISI:000275434800071, title = {Novel poly(amide-hydrazide)s and copoly(amide-hydrazide)s from Bis-(4-aminobenzyl) hydrazide and aromatic diacid chlorides: synthesis and characterization}, journal = {Journal of Applied Polymer Science}, volume = {116}, number = {4}, year = {2010}, month = {MAY}, pages = {2441-2450}, publisher = {JOHN WILEY \& SONS INC}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

A new aromatic diamine, viz., bis-(4-aminobenzyl) hydrazide (BABH), which contains preformed hydrazide and methylene linkage, was synthesized starting from alpha-tolunitrile. The BABH and intermediates involved in its synthesis were characterized by spectroscopic methods. Novel poly(amide-hydrazide)s were synthesized by low temperature solution polycondensation of BABH with isophthaloyl chloride (IPC) and terephthaloyl chloride (TPC). Furthermore, two series of copoly(amide-hydrazide)s, based on different mol \% of BABH and bis-(4-aminophenyl) ether (ODA) with IPC/TPC were also synthesized. Poly(amidehydrazide)s and copoly(amide-hydrazide)s were characterized by inherent viscosity [eta(inh)], FTIR, solubility, X-ray diffraction (MUD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The polycondensation proceeded smoothy and afforded the polymers with inherent viscosities in the range of 0.18-093 dL/g in (NMP + 4\% LiCl) at 30 degrees C +/- 0.1 degrees C. These polymers dissolved in DMAc, NMP or DMSO containing LiCl. The solubility of copolymers was considerably improved in line with less crystalline nature due to random placement of constituent monomers during the copolymerization. XRD data indicated that poly(amide-hydrazide)s from BABH alone and IPC/TPC had higher crystallinity than the corresponding copoly(amide-hydrazide)s derived from a mixture of BABH and bis-(4-aminophenyl) ether (ODA). Polymers showed initial weight loss around 160 degrees C which is attributed to the cyclodehydration leading to the formation of corresponding poly(amide-oxadiazole)s. Copolyamide-hydrazides showed, T(max) between 400 and 540 degrees C which is essentially the decomposition of poly(amide-oxadiazole)s. (C) 2010 Wiley Periodicals, Inc. J App Polym Sci 116: 2441-2450, 2010

}, keywords = {bis-(4-aminobenzyl) hydrazide, poly(amide-hydrazide), structure-property relations, Thermogravimetric analysis (TGA), x-ray diffractograms}, issn = {0021-8995}, doi = {10.1002/app.31849}, author = {Medhi, M. and Patil, A. S. and Halhalli, Mahadeo R. and Choubey, A. and Wadgaonkar, P. P. and Maldar, Noormahamad N.} } @article { ISI:000288517400019, title = {Correlation of architecture with excimer emission in 100\% pyrene-labeled self-assembled polymers}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {49}, number = {7}, year = {2011}, month = {APR}, pages = {1678-1690}, publisher = {WILEY-BLACKWELL}, address = {COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA}, abstract = {

Pyrene was incorporated as pendant unit to side-chain urethane methacrylate polymers having a short ethyleneoxy or a long polyethyleneoxy spacer segment. The short-spacer pyrene urethane methacrylate was also incorporated either as block or random copolymer (1:9) along with polystyrene. The excimer emission was observed to be different for different polymers with the random copolymer exhibiting the lowest efficiency. But, the total quantum yield was highest (phi = 0.58) for random copolymer due to the high emission coefficient of monomer compared to that of excimer. The polymer dynamics were compared by steady state emission and fluorescence decay in THF or THF/water (9:1) solvent mixture and films. The solid state decay profile showed decay without a rise time indicating presence of ground state aggregates. In THF/water (9:1), the decay profile at the excimer emission (500 nm) showed a rise time indicating dynamic excimers. The evolution of excimeric emission centred similar to 430 or similar to 480 nm as a function of temperature was also studied in THF/water (9:1). The I(E)/I(M) ratio for the lambda(343) nm excitation exhibited steady increase with temperature with the block copolymer PS-b-PIHP exhibiting the highest ratio and highest rate of increase; whereas, the random copolymer PS-r-PIHP had the lowest I(E)/I(M) ratios. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 1678-1690, 2011

}, keywords = {I(E)/I(M) ratio, Morphology, pyrene, Self-assembly, structure-property relations, time-resolved and variable temperature fluorescence}, issn = {0887-624X}, doi = {10.1002/pola.24596}, author = {Kaushlendra, K. and Deepak, V. D. and Asha, S. K.} } @article { ISI:000340414900005, title = {Effect of the branching pattern of hydrophobic dendrons on the core structure of linear-dendritic copolymer micelles}, journal = {Macromolecular Chemistry and Physics}, volume = {215}, number = {15}, year = {2014}, month = {AUG}, pages = {1456-1465}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Hydrophobic dendrons based on different branching patterns, viz. 3,5-di- and 3,4,5-trisubstituted phenyl rings, consist of the same backbone but exhibit different sizes, shapes, and hydrophobic densities. These dendrons are attached to poly(ethylene glycol) and the core properties of the copolymer micelles are investigated in tetrahydrofuran (THF)/water mixtures by neutron scattering. Two polymers with intermediate hydrophobicity are studied further with variations in the solvent composition and the temperature. The aggregation numbers for 3,4,5-based dendron copolymers are lower, with more THF molecules of solvation compared with the 3,5-based dendron copolymer, the difference being greater at higher generations due to different molecular shapes. The micellar core size increases in small steps with dendron size so that dye encapsulation is tuned.

}, keywords = {diblock copolymers, linear-dendritic copolymers, micelles, neutron scattering, structure-property relations}, issn = {1022-1352}, doi = {10.1002/macp.201400150}, author = {Kalva, Nagendra and Aswal, Vinod K. and Ambade, Ashootosh V.} } @article { ISI:000381302400017, title = {P4VP and oligo(phenylenevinylene)-perylenebisimide mixed donor-acceptor supramolecular comb polymer complexes with improved charge carrier mobility}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {54}, number = {15}, year = {2016}, month = {AUG}, pages = {2403-2412}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

Random donor-acceptor (D-A) supramolecular comb polymers were formed when hydroxyl functionalized donor and acceptor small molecules based on Oligo(phenylenevinylene) (named OPVCN-OH) and Perylenebisimide (named UPBI-PDP), respectively, were complexed with Poly(4-vinyl pyridine) (P4VP). A series of random D-A supramolecular comb polymers were formed by varying the ratios of UPBI-PDP and OPVCN-OH with P4VP. A 100\% P4VP-donor polymer complex [P4VP(OPV1.00)] and a 100\% P4VP-acceptor polymer complex [P4VP(UPBI1.00)] were also synthesized and characterized. Complex formation was confirmed by FT-IR and H-1 NMR spectroscopy. Solid state structural studies carried out using small angle X-ray scattering and wide angle X-ray diffraction experiments revealed altered packing of the D and A molecules in the complexes. Transmission electron microscopy images showed lamellar structures in the \<10 nm scale for the P4VP(OPV1.00), P4VP(UPBI1.00), and mixed P4VP (D-A) complexes. The effect of the nanoscopic D-A self-assembly on the bulk mobility of the materials was probed using SCLC measurements. The mixed D-A random complexes exhibited ambipolar charge transport characteristics with higher values for the average bulk hole mobility estimate. P4VP(OPV0.25+UPBI0.75) exhibited an average hole mobility in the order of 10(-2) cm(2) V-1 s(-1) and electron mobility 10(-5) cm(2) V-1 s(-1). (C) 2016 Wiley Periodicals, Inc.

}, keywords = {donor-acceptor, oligo(phenylenevinylene), P4VP, Perylenebisimide, Self-assembly, structure-property relations, supramolecular comb polymer, supramolecular structures}, issn = {0887-624X}, doi = {10.1002/pola.28115}, author = {Saibal, B. and Chithiravel, Sundaresan and Asha, S. K.} } @article {43796, title = {Partially bio-based poly(amide imide)s by polycondensation of aromatic diacylhydrazides based on lignin-derived phenolic acids and aromatic dianhydrides: synthesis, characterization, and computational studies}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {55}, year = {2017}, month = {NOV}, pages = {3636-3645}, type = {Article}, abstract = {

Two new bio-based diacylhydrazide monomers, namely, 4,4-(propane-1,3-diylbis(oxy))bis(3-methoxybenzohydrazide) and 4,4-(propane-1,3-diylbis(oxy))bis(3,5-dimethoxybenzohydrazide) were synthesized starting from lignin-derived phenolic acids, namely, vanillic acid and syringic acid. A series of poly(amide imide)s was synthesized by polycondensation of these diacylhydrazide monomers with commercially available aromatic dianhydrides. Poly(amide imide)s showed inherent viscosity in the range 0.44-0.56 dLg(-1) and exhibited good solubility in organic solvents. Poly(amide imide)s could be cast into transparent, flexible, and tough films from their N,N-dimethylacetamide solutions. Poly(amide imide)s showed 10\% weight loss in the temperature range 340-364 degrees C indicating their good thermal stability. Glass transition temperature (T-g) of poly(amide imides)s were measured by DSC and DMA which were in the range 201-223 degrees C and 214-248 degrees C, respectively. The T-g values of poly(amide imide)s were dependent on the number methoxy substituents on aromatic rings of diacylhydrazide monomers. Molecular dynamics simulation studies revealed that chain rigidity is the dominant factor for observed trends in T-g. (c) 2017 Wiley Periodicals, Inc.

}, keywords = {Biobased Polymers, Computational studies, Glass-transaction temperature, lignin, Monomers, Plant oils, Polyimide, Reneable resources, Renewable resources, Step-growth polymers, structure-property relations, Sustanaible Polymers, Thermal night, Thermosetting resins, Vanillin}, issn = {0887-624X}, doi = {10.1002/pola.28748}, author = {Kuhire, Sachin S. and Sharma, Pragati and Chakrabarty, Suman and Wadgaonkar, Prakash P.} } @article {44241, title = {Synthesis, characterization, and gas permeation properties of adamantane-containing polymers of intrinsic microporosity}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {56}, year = {2018}, month = {JAN }, pages = {16-24}, type = {Article}, abstract = {

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.

}, keywords = {adamantane, Gas permeation, intrinsic microporosity, membranes, structure-property relations}, issn = {0887-624X}, doi = {10.1002/pola.28710}, author = {Shrimant, Bharat and Shaligram, Sayali V. and Kharul, Ulhas K. and Wadgaonkar, Prakash P.} }