01573nas a2200205 4500008004100000022001400041245006500055210006100120260009800181300001400279490000700293520081400300653001501114653003201129653002901161653002601190100003401216700002501250856009201275 2005 eng d a0959-810300aSynthesis of poly(1-hexene)s end-functionalized with phenols0 aSynthesis of poly1hexenes endfunctionalized with phenols aTHE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLANDbJOHN WILEY & SONS LTDcSEP a1310-13130 v543 a

Electrophilic alkylations of phenol/2,6-dimethylphenol were performed with vinylidene-terminated poly(1-hexene)s using BF3-OEt2 catalyst. Vinylidene-terminated poly(1-hexene)s with M. varying from 400 to 10000 were prepared by bulk polymerization of 1-hexene at 50 to -20 degrees C using Cp2ZrCl2/MAO catalysts. The phenol/2,6-dimethylphenol-terminated poly(1-hexene)s was characterized by NMR (H-1, C-13), UV, IR and vapor phase osmometer (VPO). The isomer distribution (ortho, para and ortholpara) was determined by P-13 NMR using a phosphitylating reagent, namely 2-chloro-1,3,2-dioxaphospholane. The number-average degree of functionality (F-n) > 0.9 with > 95% para selectivity could be achieved using low-molecular-weight oligomers of poly(1-hexene)s. (c) 2005 Society of Chemical Industry.

10aAlkylation10achain-end functionalization10afunctional poly(olefin)s10ametallocene catalysts1 aYanjarappa, Mallinamadugu, J.1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/synthesis-poly1-hexenes-end-functionalized-phenols-001355nas a2200193 4500008004100000022001400041245012800055210006900183260010600252300001400358490000700372520053300379100002600912700002300938700002200961700002600983700002501009856012701034 2006 eng d a0040-403900aNaIO4/KI/NaCl: a new reagent system for iodination of activated aromatics through in situ generation of iodine monochloride0 aNaIO4KINaCl a new reagent system for iodination of activated aro aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJUL a4793-47960 v473 a

A new reagent system consisting of NaIO4/KI/NaCl in aq AcOH has been found to be effective in iodinating a variety of activated aromatic substrates via in situ-generated iodine monochloride, to furnish iodoaromatics in excellent yields. This iodination procedure has been applied successfully for a cost-effective synthesis of 3,3'-diaminobenzidine, a key intermediate for preparing proton conducting membranes for fuel cell applications, with high yield and a purity of 99.7%. (c) 2006 Elsevier Ltd. All rights reserved.

1 aEmmanuvel, Lourdusamy1 aShukla, Ravi, Kant1 aSudalai, Arumugam1 aGurunath, Suryavanshi1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/naio4kinacl-new-reagent-system-iodination-activated-aromatics-through-situ-generation-002004nas a2200217 4500008004100000022001400041245010200055210006900157260009800226300001200324490000700336520117300343653004001516653001701556653001101573653002301584653000801607100001901615700002501634856012701659 2006 eng d a0959-810300aSilica-supported bis(imino)pyridyl iron(II) catalyst: nature of the support-catalyst interactions0 aSilicasupported bisiminopyridyl ironII catalyst nature of the su aTHE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLANDbJOHN WILEY & SONS LTDcAUG a854-8610 v553 a

Ethylene polymerizations were performed using silica-supported 2,6-bis[1-(2,6-diisopropylphenylimino) ethyl] pyridine iron(II) dichloride with methylaluminoxane (MAO) as co-catalyst. Silica was calcined at 600, 400 and 200 degrees C under vacuum for 8 h. The effect of calcination temperature of silica on the polymerization activity and the properties of the polymers obtained were examined. Catalyst-support interactions were examined by both a chemical method and XPS. It was observed that upon supporting the catalyst on the surface of silica, there is an increase in the binding energy of the metal center. However, no change in the metal binding energy was observed on supporting the catalyst to silica calcined at different temperatures. Ethylene polymerizations were performed using MAO as co-catalyst. Catalysts were also prepared by first pretreating silica with NIAO, followed by addition of the Fe(II) catalyst and contacting a complex of Fe(II) catalyst-MAO with silica previously calcined at 400 degrees C for 8 h. The results indicate that there is no chemical bonding between the support and the catalyst. (C). 2006 Society of Chemical Industry.

10abis(imino) pyridyl iron(II) complex10aPolyethylene10asilica10asupported catalyst10aXPS1 aRay, Saptarshi1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/silica-supported-bisiminopyridyl-ironii-catalyst-nature-support-catalyst-interactions-102127nas a2200229 4500008004100000022001400041245016000055210006900215260006800284300001400352490000700366520120600373653002201579653001901601653002901620653001301649653002201662653002701684100002901711700002501740856013201765 2007 eng d a0887-624X00aKinetics of hexene-1 polymerization using [(N,N `-diisopropylbenzene)-2,3-(1,8-napthyl)-1,4-diazabutadiene] dibromonickel/methylaluminoxane catalyst system0 aKinetics of hexene1 polymerization using NN diisopropylbenzene23 a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcMAR a1093-11000 v453 a

{Kinetics of hexene-1 polymerization was investigated using [(N,N'-diiso-propylbenzene)2,3-(1,8-napthly)-1,4-diazabutadiene]/dibro monickel/methylaluminoxane catalyst. Experiments were performed at varying catalyst and monomer concentrations in the temperature range of -10 to 35 degrees C. First order time-conversion plot shows a downward curvature at temperatures of 20 degrees C and 35 degrees C indicating the presence of finite termination reactions. A nonlinear plot of degree of polymerization (P-n) with respect to conversion indicates occurrence of transfer reactions and slow initiation. The experimental molar masses are higher than predicted, which implies that a fraction of catalyst species could not be activated or is deactivated at the early stages of the reactions. The efficiency of the catalyst (Cat(eff)) varies from 0.77 to 0.89. The observed polydispersity of the poly(hexene-1) s is in the range of 1.18-1.48. The reaction order was found to be 1.11 with respect to catalyst. The Arrhenius plot obtained using the overall propagation rate constant, k(p), at five different temperatures (-10, 0, 10, 20, and 35 degrees C) was found to be linear with an activation energy

10aActivation energy10achain transfer10adegree of polymerization10ahexene-110akinetics (polym.)10anickel (alpha-diimine)1 aSubramanyam, Ummadisetty1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/kinetics-hexene-1-polymerization-using-nn-diisopropylbenzene-23-18-napthyl-14-diazabutadiene01639nas a2200241 4500008004100000022001400041245017900055210006900234260006800303300001200371490000700383520068300390653001801073653002001091653002101111653002001132653002701152653000801179653002401187100002901211700002501240856013201265 2007 eng d a0887-624X00aSynthesis and characterization of poly(higher-alpha-olefin)s with a nickel(alpha-diimine)/methylaluminoxane catalyst system: effect of chain running on the polymer properties0 aSynthesis and characterization of polyhigheralphaolefins with a  a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcJAN a191-2100 v453 a

Homopolymerization of octadecene-1 at different reaction conditions has been studied. Significant chain running can be seen at higher polymerization temperatures. Interestingly, insertion of octadecene-1 into a sterically hindered nickel-cation/carbon (secondary) bond is observed. The microstructure of the polymer was established using NMR spectroscopy. The effects of chain running on polymer melting, crystallization behavior, and dynamic mechanical thermal properties were studied using DSC and DMTA. The extent of chain running (i.e., 2 omega-, 1,omega-enchainments) decreases with an increase in the carbon number of alpha-olefins. (c) 2006 Wiley Periodicals, Inc.

10achain running10aCrystallization10aglass transition10amelt transition10anickel (alpha-diimine)10aNMR10apoly(alpha-olefin)s1 aSubramanyam, Ummadisetty1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/synthesis-and-characterization-polyhigher-alpha-olefins-nickelalpha-diiminemethylaluminoxane02142nas a2200205 4500008004100000022001400041245015500055210006900210260006800279300001400347490000700361520130500368653002701673653002101700653001401721100002601735700002301761700002501784856012701809 2008 eng d a0887-624X00aSynthesis of amphiphilic poly(methyl methacrylate-b-ethylene oxide) copolymers from monohydroxy telechelic poly(methyl methacrylate) as macroinitiator0 aSynthesis of amphiphilic polymethyl methacrylatebethylene oxide  a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcMAR a2132-21440 v463 a

The synthesis of well-defined poly(methyl methacrylate)-block-poly(ethylene oxide) (PMMA-b-PEO) dibock copolymer through anionic polymerization using monohydroxy telechelic PMMA as macroinitiator is described. Living anionic polymerization of methyl methacrylate was performed using initiators derived from the adduct of diphenylethylene and a suitable alkyllithium, either of which contains a hydroxyl group protected with tert-butyldimethylsilyl moiety in tetrahydrofuran (THF) at -78 degrees C in the presence of LiClO4. The synthesized telechelic PMMAs had good control of molecular weight with narrow molecular weight distribution (MWD). The H-1 NMR and MALDI-TOF MS analysis confirmed quantitative functionalization of chain-ends. Block copolymerization of ethylene oxide was carried out using the terminal hydroxyl group of PMMA as initiator in the presence of potassium counter ion in THF at 35 degrees C. The PMMA-b-PEO diblock copolymers had moderate control of molecular weight with narrow MWD. The H-1 NMR results confirm the absence of trans-esterification reaction of propagating PEO anions onto the ester pendants of PMMA. The micellation behavior of PMMA-b-PEO diblock copolymer was examined in water using H-1 NMR and dynamic light scattering. (C) 2008 Wiley Periodicals, Inc.

10aAnionic polymerization10ablock copolymers10asynthesis1 aDhara, Mahua, Ganguly1 aBaskaran, Durairaj1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/synthesis-amphiphilic-polymethyl-methacrylate-b-ethylene-oxide-copolymers-monohydroxy-001588nas a2200217 4500008004100000022001400041245008100055210006900136260008600205300001800291490000700309520076700316653002701083653002901110653001701139100002601156700002501182700002301207700003001230856011001260 2009 eng d a1060-132500aSynthesis of hydroxy-functional PMMA macromonomers by anionic polymerization0 aSynthesis of hydroxyfunctional PMMA macromonomers by anionic pol a325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USAbTAYLOR & FRANCIS INCcSEP aPII 9144946340 v463 a

Living anionic polymerization has been utilized to synthesize hydroxy end-functionalized PMMA macromonomers with styryl or allyl functionalities as the polymerizable end-groups. Protected hydroxy-functionalized alkyl lithium initiators have been used to initiate anionic polymerization of MMA. Subsequently the living chains with protected hydroxyl function have been terminated using 4-vinylbenzyl chloride (4-VBC) or allyl methacrylate (ALMA) to form -hydroxy–styryl and -hydroxy–allyl PMMA, respectively. These protected hydroxy-functionalized PMMA macromonomers have been characterized by GPC and 1H-NMR. Termination using 4-VBC led to 50% functionalization, whereas that using allyl methacrylate led to 100% functionalization of the hydroxy-PMMA.

10aAnionic polymerization10afunctionalized initiator10aMacromonomer1 aDhara, Mahua, Ganguly1 aSivaram, Swaminathan1 aBhonde, Ramesh, R.1 aPrasad, Bhagavatula L. V. uhttps://library.ncl.res.in/content/synthesis-hydroxy-functional-pmma-macromonomers-anionic-polymerization01718nas a2200205 4500008004100000022001400041245008500055210006900140260005700209300001200266490000700278520096900285653002701254653001801281653002301299100002601322700002501348700002301373856011601396 2009 eng d a0170-083900aSynthesis of hydroxy-functionalized star-branched PMMA by anionic polymerization0 aSynthesis of hydroxyfunctionalized starbranched PMMA by anionic  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcAUG a185-1960 v633 a

Living anionic polymerization has been exploited to synthesize hydroxy end-functionalized PMMA star-branched polymers. Protected hydroxy-functionalized alkyl lithium initiators have been used to initiate anionic polymerization of MMA. Subsequently the living chains with protected hydroxyl function have been used to cross-link ethylene glycol dimethacrylate (EGDMA) in order to form star-branched polymers with cross-linked EGDMA core via `arm-first' method. The linear arms and the star molecules have been characterized by (1)HNMR, GPC, and light scattering. Variation in the number of arms with arm molecular weight and cross-linker loading has been studied. Star-branched PMMA-OH with as many as similar to 10 arms could be successfully made. Increased molecular weight of PMMA-OH led to decrease in the number of arms incorporated due to increased steric hindrance on the core. Increase in EGDMA concentration slightly increased the arm incorporation.

10aAnionic polymerization10aStar polymers10aStar-branched PMMA1 aDhara, Mahua, Ganguly1 aSivaram, Swaminathan1 aBaskaran, Durairaj uhttps://library.ncl.res.in/content/synthesis-hydroxy-functionalized-star-branched-pmma-anionic-polymerization-001413nas a2200229 4500008004100000022001400041245008200055210006900137260008600206300001800292490000700310520060700317653000600924653001500930653001500945653002200960653001500982653002400997100002701021700002501048856011001073 2010 eng d a0039-791100aAddition of a silyl ketene acetal to alpha,beta-unsaturated cyclic anhydrides0 aAddition of a silyl ketene acetal to alphabetaunsaturated cyclic a325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USAbTAYLOR & FRANCIS INCcJUL aPII 9247712650 v403 a

Addition of [1-methoxy-2 methyl-1-propenyl)-oxy] trimethylsilane (MTS) to unsymmetrical ,-unsaturated cyclic anhydrides (namely, itaconic anhydride and citraconic anhydride) as well as symmetrical anhydrides (namely, maleic anhydride and 2,3-dimethylmaleic anhydride) was investigated. Itaconic anhydride isomerizes to citraconic anhydride in the presence of MTS. In the presence of Lewis acid catalysts (Yb(OTf)3/CH2Cl2), MTS adds to itaconic anhydride at room temperature in a 1,4-fashion. 1,2-Addition is the preferred pathway with both 2,3-dimethyl maleic anhydride and citraconic anhydride.

10a110a2-Addition10a4-addition10acyclic anhydrides10aLewis acid10aSilyl ketene acetal1 aGnaneshwar, Rudhramyna1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/addition-silyl-ketene-acetal-alphabeta-unsaturated-cyclic-anhydrides-000592nas a2200169 4500008004100000022001400041245004800055210004700103260007700150300001200227490000700239100002300246700002600269700002500295700002500320856007700345 2013 eng d a1433-785100aChemistry in India: unlocking the potential0 aChemistry in India unlocking the potential aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcDEC a114-1170 v521 aArunan, Elangannan1 aBrakaspathy, Ramasamy1 aDesiraju, Gautam, R.1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/chemistry-india-unlocking-potential-001609nas a2200205 4500008004100000022001400041245004500055210004200100260007100142300001400213490000700227520095400234100002101188700002101209700002501230700002401255700002101279700002301300856008001323 2015 eng d a0024-929700aStar telechelic poly(L-lactide) ionomers0 aStar telechelic polyLlactide ionomers a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a6580-65880 v483 a

Poly(L-lactide) (PLA), a biodegradable and biorenewable polymer, has many excellent properties that are equivalent to those of petroleum-derived plastics such as polystyrene, aromatic polyesters, etc. However, a major disadvantage of PLA which limits its processability is its poor melt elasticity. In this work we explore the possibility of improving the viscoelastic properties of PLA melt by incorporating ionic groups on the polymer. Specifically, we demonstrate the synthesis of star telechelic PLA anionomers by a three-step procedure involving synthesis of Star PIA, converting the hydroxyl end groups into carboxylic acid end groups, and finally converting these into ionic groups. Rheology data showed a dramatic increase in the elasticity of the star telechelic ionomer melts relative to the Star PLA melts. The viscoelasticity of star telechelic ionomers melts could be modulated by varying the number of ionic groups per molecule.

1 aKulkarni, Amruta1 aLele, Ashish, K.1 aSivaram, Swaminathan1 aRajamohanan, P., R.1 aVelankar, Sachin1 aChatterji, Apratim uhttps://library.ncl.res.in/content/star-telechelic-polyl-lactide-ionomers-000527nas a2200121 4500008004100000022001400041245011400055210006900169260000900238490000800247100002500255856012500280 2016 eng d a0065-772700aFunctional additives derived from structurally well-defined poly(olefin)s: Structure - function relationships0 aFunctional additives derived from structurally welldefined polyo cAUG 0 v2521 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/functional-additives-derived-structurally-well-defined-polyolefins-structure-function02096nas a2200229 4500008004100000022001400041245020100055210006900256260006700325490000800392520112200400653001801522653001501540653003801555653002601593653003201619100002201651700002401673700002301697700002501720856012101745 2016 eng d a0021-899500aSynthesis and characterization of well-defined random and block copolymers of epsilon-caprolactone with l-lactide as an additive for toughening polylactide: Influence of the molecular architecture0 aSynthesis and characterization of welldefined random and block c a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcAPR0 v1333 a

Well-defined multiarmed star random and block copolymers of epsilon-caprolactone with l-lactide with controlled molecular weights, low polydispersities, and precise numbers of arms were synthesized by the ring-opening polymerization of respective cyclic ester monomers. The polymers were characterized by H-1-NMR and C-13-NMR to determine their chemical composition, molecular structure, degree of randomness, and proof of block copolymer formation. Gel permeation chromatography was used to establish the degree of branching. Star-branched random copolymers exhibited lower glass-transition temperatures (T-g's) compared to a linear random copolymer. When the star random copolymers were melt-blended with poly(l-lactic acid) (PLA), we observed that the elongation of the blend increased with the number of arms of the copolymer. Six-armed block copolymers, which exhibited higher T-g's, caused the maximum improvement in elongation. In all cases, improvements in the elongation were achieved with no loss of stiffness in the PLA blends. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43267.

10abiodegradable10acopolymers10adifferential scanning calorimetry10amechanical properties10aring-opening polymerization1 aDeokar, Megha, D.1 aIdage, Susheela, B.1 aIdage, Bhaskar, B.1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/synthesis-and-characterization-well-defined-random-and-block-copolymers-epsilon-001921nas a2200229 4500008004100000245013300041210006900174260000800243300001200251490000800263520107600271100001701347700002901364700001601393700002901409700002501438700002601463700002401489700002501513700003201538856012101570 2017 eng d00aThermally conductive thin films derived from defect free graphene-natural rubber latex nanocomposite: preparation and properties0 aThermally conductive thin films derived from defect free graphen cAUG a527-5340 v1193 aCommercially useful rubber products viz. gloves, condoms, tyres, and rubber hoses used in high temperature environments, etc., require efficient thermal conductivity, which increases the lifetime of these products. Graphene can fetch this property, if it is effectively incorporated into the rubber matrix. The great challenge in preparing graphene-rubber nanocomposites is formulating a scalable method to produce defect free graphene and its homogeneous dispersion into polymer matrices through an aqueous medium. Here, we used a simple method to produce defect free few layer (2-5) graphene, which can be easily dispersed into natural rubber (NR) latex without adversely affecting its colloidal stability. The resulting new composite showed large increase in thermal conductivity (480-980%) along with 40% increase in tensile properties and 60% improvement in electrical conductivity. This study provides a novel and generalized approach for the preparation of graphene based thermally conductive rubber nanocomposites. (C) 2017 The Authors. Published by Elsevier Ltd.1 aGeorge, Gejo1 aSisupal, Suja, Bhargavan1 aTomy, Teenu1 aPottammal, Bincy, Akkoli1 aKumaran, Alaganandam1 aSuvekbala, Vemparthan1 aGopimohan, Rajmohan1 aSivaram, Swaminathan1 aRagupathy, Lakshminarayanan uhttps://library.ncl.res.in/content/thermally-conductive-thin-films-derived-defect-free-graphene-natural-rubber-latex02205nas a2200229 4500008004100000022001400041245015700055210006900212260000800281300001000289490000600299520135100305100001701656700002901673700001601702700002501718700002101743700002601764700002501790700003201815856012801847 2018 eng d a2045-232200aFacile, environmentally benign and scalable approach to produce pristine few layers graphene suitable for preparing biocompatible polymer nanocomposites0 aFacile environmentally benign and scalable approach to produce p cJUL a112280 v83 a

The success of developing graphene based biomaterials depends on its ease of synthesis, use of environmentally benign methods and low toxicity of the chemicals involved as well as biocompatibility of the final products/devices. We report, herein, a simple, scalable and safe method to produce defect free few layers graphene using naturally available phenolics i.e. curcumin/tetrahydrocurcumin/ quercetin, as solid-phase exfoliating agents with a productivity of similar to 45 g/batch (D/G = 0.54 and D/D' <= 1.23). The production method can also be employed in liquid-phase using a ball mill (20 g/batch, D/G <= 0.23 and D/D' <= 1.12) and a sand grinder (10 g/batch, D/G <= 0.11 and D/D similar to = 0.78). The combined effect of p-p interaction and charge transfer (from curcumin to graphene) is postulated to be the driving force for efficient exfoliation of graphite. The yielded graphene was mixed with the natural rubber (NR) latex to produce thin film nanocomposites, which show superior tensile strength with low modulus and no loss of % elongation at break. In-vitro and in-vivo investigations demonstrate that the prepared nanocomposite is biocompatible. This approach could be useful for the production of materials suitable in products (gloves/condoms/catheters), which come in contact with body parts/ body fluids.

1 aGeorge, Gejo1 aSisupal, Suja, Bhargavan1 aTomy, Teenu1 aKumaran, Alaganandam1 aVadivelu, Prabha1 aSuvekbala, Vemparthan1 aSivaram, Swaminathan1 aRagupathy, Lakshminarayanan uhttps://library.ncl.res.in/content/facile-environmentally-benign-and-scalable-approach-produce-pristine-few-layers-graphene01916nas a2200193 4500008004100000245010800041210006900149260000800218300001400226490000700240520121800247100001701465700002401482700002001506700002301526700002801549700002501577856012001602 2018 eng d00aSoluble polybenzimidazoles with intrinsic porosity: synthesis, structure, properties and processability0 aSoluble polybenzimidazoles with intrinsic porosity synthesis str cMAY a1046-10570 v563 aWe have explored two novel comonomers, namely, 4,16-dicarboxyl[2.2]paracyclophane and 5,5,6,6-tetraamino-3,3,3,3-tetramethyl-1,1-spirobi[indane], for the synthesis of co-polybenzimidazoles (co-PBIs) with intrinsic porosity. Both these monomers possess twisted structures that can lead to awkward macromolecular shapes that cannot pack efficiently. The consequences of introducing these two monomers on the structure and properties of PBIs are reported. The random copolymers synthesized are amorphous and possess glass transition temperatures (T(g)s) greater than 400 degrees C. T-g decreases with increasing comonomer content indicating an increase in fractional free volume. The copolymers have low surface area. TEM and BET measurements show evidence of mesopore formation. The copolymers show significant carbon dioxide adsorption. Single chain molecular dynamics simulation of 24-mer repeat units shows intramolecular void spaces arising as a result of distorted polymer chain with reduced conformational mobility. These studies define a new synthetic strategy for bottoms-up synthesis of PBIs with intrinsic porosity. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1046-10571 aKumar, Vikas1 aChatterjee, Shyambo1 aSharma, Pragati1 aChakrabarty, Suman1 aAvadhani, Chilukuri, V.1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/soluble-polybenzimidazoles-intrinsic-porosity-synthesis-structure-properties-and02657nas a2200217 4500008004100000022001400041245015700055210006900212260000800281300001400289490000800303520182900311100001702140700002102157700002602178700002802204700002702232700002802259700002502287856012702312 2019 eng d a1932-744700aLithium speciation in the LiPF6/PC electrolyte studied by two dimensional heteronuclear overhauser enhancement and pulse field gradient diffusometry NMR0 aLithium speciation in the LiPF6PC electrolyte studied by two dim cAPR a9661-96720 v1233 a

Electrolytic dissociation of lithium hexafluorophosphate (LiPF6) in the nonaqueous cyclic propylene carbonate (PC) has been investigated in the wide range of concentration (0.05-3.5 M) by Li-7 solution-state nuclear magnetic resonance (NMR) spectroscopy. Two-dimensional heteronuclear Overhauser enhancement spectroscopy NMR experiments have not only enabled the cation solvation and ion-pairing to be directly monitored but additionally evidence anion solvent interaction at higher concentrations (>1.2 M) of the PC electrolyte. Preliminary analysis of kinetic nOe data has been made to determine site-dependent cross-relaxation rates for the spatial interaction of the solvent with the Li+ cation and the PF6- anion. The concentration dependence of the Li-7 NMR self-diffusion coefficient (D-self), determined using very strong pulsed magnetic field gradients (similar to 1700 Gauss/cm), depicts two breaks to mark the solvation and ion-pairing events in a distinct manner. This in turn has aided the determination of solvent coordination number and average sizes of solvated and ion-paired clusters. Our results indicate that in the contact ion pair (CIP)-dominated electrolyte (>2 M), lithium-ion mobility across the solvated and ion-paired environments appears to be inhibited which makes the spectral distinction of solvated and ion-paired environments possible. The concentration dependence of the Li-7 NMR spectral and diffusometry data is in striking correspondence with that of bulk conductivity measurements and point to the detrimental effect of CIP aggregates in impeding the ionic conductivity at high salt concentrations. These results have significance in understanding the structure and dynamics of lithium-ion solvates that are ubiquitous in the working environment of a lithium-ion battery.

1 aKumar, Vikas1 aReddy, Ravikanth1 aKumar, B., V. N. Phan1 aAvadhani, Chilukuri, V.1 aGanapathy, Subramanian1 aChandrakumar, Narayanan1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/lithium-speciation-lipf6pc-electrolyte-studied-two-dimensional-heteronuclear-overhauser02184nas a2200217 4500008004100000022001400041245010000055210006900155260000800224300001200232490000600244520143500250653002901685653001701714653002701731653001501758653001901773100002101792700002501813856012801838 2019 eng d a2194-428800aSeparator membranes for lithium-sulfur batteries: design principles, structure, and performance0 aSeparator membranes for lithiumsulfur batteries design principle cJUN a18008190 v73 a

Improvement in electrical energy storage systems is one of the most recent research topics of great academic and industrial interest. Lithium-sulfur (Li-S) battery systems offer a theoretical energy density an order of magnitude larger than the popular Li-ion batteries. The principle of working, inherent challenges in utilizing this system for commercial applications, and the various approaches taken to address these challenges are herein discussed in detail. The polysulfide shuttle effect is a major concern that deteriorates electrochemical performance in this system. In the recent past, electrodes have been intricately engineered to tackle this problem. However, more recently, the focus has shifted to the critical role of the separator. Modifying conventional separators or fabricating novel structures to enhance the cell performance appears to be a more feasible option. Some design principles that are critical to the functioning of a separator in Li-S batteries, namely physisorption, chemisorption, and electrostatic repulsion, are discussed. Many recent papers proposed novel cell configurations with specifically designed functional separators. These reports are classified according to three design principles, analyzed critically, and compared with a view to assess their relative merits and efficacy. Some thoughts on the future directions in the development of an efficient separator are described.

10alithium-sulfur batteries10apolysulfides10arechargeable batteries10aseparators10ashuttle effect1 aGupta, Aritrajit1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/separator-membranes-lithium-sulfur-batteries-design-principles-structure-and-performance02005nas a2200229 4500008004100000022001400041245010700055210006900162260000800231300001100239490000800250520119300258653002501451653002401476653002101500653002201521653004101543100001701584700002401601700002501625856012501650 2020 eng d a0079-670000aUltrahigh molecular weight polyethylene: catalysis, structure, properties, processing and applications0 aUltrahigh molecular weight polyethylene catalysis structure prop cOCT a1012900 v1093 a

Ultrahigh molecular weight polyethylene (UHMWPE) belongs to an emerging class of high-performance specialty polymers with a unique set of properties and applications. The field has witnessed many scientific and technological advances in recent years. However, synthesis of UHMWPE is not a trivial exercise and presents several challenges. This review addresses these fundamental challenges and provides an overview of recent developments in the field of UHMWPE. The nature of catalysts, reaction conditions that favor its formation, their physical properties, methods of processing them into products, and their applications are discussed. Recent developments in formation of UHMWPE in a disentangled state by use of appropriate catalysts and reaction conditions are also discussed. This has elicited considerable interest as a means of enabling melt processing of UHMWPE. This review provides a comprehensive source of information and understanding of the multifaceted aspects of UHMWPE with specific reference to chemistry, catalysis, processes for manufacturing, and an analysis of catalyst structure-polymer property relationships. (C) 2020 Elsevier B.V. All rights reserved.

10aCatalysts for UHMWPE10aDisentangled UHMWPE10aEntangled UHMWPE10apolyethylene (PE)10aUltrahigh molecular weight (UHMW) PE1 aPatel, Ketan1 aChikkali, Samir, H.1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/ultrahigh-molecular-weight-polyethylene-catalysis-structure-properties-processing-and02390nas a2200169 4500008004100000022001400041245016500055210006900220260000800289300001400297490000600311520170100317100002202018700002802040700002502068856012702093 2022 eng d a2470-134300aToughening poly(l-lactide) blends: effectiveness of sequence-controlled six-arm star-branched block copolymers of poly(L-lactide) and poly(epsilon-caprolactone)0 aToughening polyllactide blends effectiveness of sequencecontroll cMAR a9118-91290 v73 a

Well-defined six-arm star-branched bio-degradable block copolymers of L-lactide and epsilon-caprolactone were prepared using controlled ring-opening polymerization and a sequential monomer addition method using dipentaerythritol as the initiator core and organocatalysts at low temperatures in solution. Sequence of enchainment was changed by reversing the order of monomer addition giving, either, a crystalline PLA block or an amorphous PCL block as the outer segment. Well-defined six-arm poly(epsilon-caprolactone-b-L-lactide, 6s-PCL-b-PLA) block copolymers were obtained with a range of segment molecular weights. However, in the case of six-arm poly(L-lactide-b-epsilon-caprolactone, 6s-PLA-b-PCL), disruption of the block structure was observed on account of competing transesterification reactions accompanying a chain-growth reaction. Such sequence-controlled block copolymers showed interesting phase morphologies, as evidenced by differential scanning calorimetry (DSC) studies. 6s-PCL-b-PLA showed two glass-transition temperatures and two melting temperatures characteristic of the amorphous and crystalline blocks. 6s-PCL-b-PLA and 6s-PLA-b-PCL with different segment chain lengths were solution blended (10 wt %) with a commercially sourced PLA. All the blends were highly transparent. The structure and properties of the blend were examined by DSC, measurement of mechanical properties, and scanning electron microscopy. The results show that a phase-separated 6s-PCL-b-PLA copolymer results in two- to three-fold improvement in tensile toughness without the loss of modulus. A possible hypothesis for the mechanism of tensile toughness in the blend has been proposed.

1 aDeokar, Megha, D.1 aGarnaik, Baijayantimala1 aSivaram, Swaminathan uhttps://library.ncl.res.in/content/toughening-polyl-lactide-blends-effectiveness-sequence-controlled-six-arm-star-branched00836nas a2200229 4500008004100000022001400041245011000055210006900165260000900234300001400243490000700257653001700264653003400281100002600315700002200341700001900363700002700382700002400409700002500433700002200458856012600480 2024 eng d a2155-543500aSolvent-free hydroxylation of unactivated C-H bonds in small molecules and macromolecules by a Fe complex0 aSolventfree hydroxylation of unactivated CH bonds in small molec cAPR  a7173-71810 v1410aBall milling10asolid-state C-H hydroxylation1 aChatterjee, Debasmita1 aSajeevan, Amritha1 aJana, Sandipan1 aBirajdar, Rajkumar, S.1 aChikkali, Samir, H.1 aSivaram, Swaminathan1 aGupta, Sayam, Sen uhttps://library.ncl.res.in/content/solvent-free-hydroxylation-unactivated-c-h-bonds-small-molecules-and-macromolecules-fe02842nas a2200217 4500008004100000022001400041245010600055210006900161260000800230300001400238490000700252520209100259100001702350700002102367700001902388700003002407700001802437700002502455700002202480856012202502 2025 eng d a2050-748800aShola: a 3D porous hydrophobic-oleophilic lignocellulosic material for efficient oil/water separation0 aShola a 3D porous hydrophobicoleophilic lignocellulosic material cJAN a1983-19950 v133 a

Transitioning from the fossil fuel era to a sustainable future requires increasing adoption of high-performing renewable materials in industrial applications. Natural polymers derived from lignocellulosic materials are often considered more environmentally friendly than their petroleum-based synthetic analogs. Aeschynomene aspera, commonly known as Shola, has been found to be a large source of amorphous cellulose and a useful sorbent for the removal of oil from water. The Shola pith, the pure white inner stem, is rich in cellulose and has an exquisite three-dimensional and hierarchical porous architecture created by nature. The pith consists of about 70 wt% cellulose as the main chemical component, which is much higher than what is found in other lignocellulosic sources. In addition, the pith has about 12 wt% hemicellulose, 2-3 wt% pectin, 10 wt% lignin, 2.5 wt% wax, and 2 wt% protein as other chemical components. It was observed that water has a high contact angle (135 degrees) on the surface of the pith, while oil droplets instantly spread on the surface, indicating excellent hydrophobic-oleophilic properties. Further studies reveal that the Shola pith exhibits a fast and high sorption capacity of 40-60 g/g for various oils and organic liquids. Silicone oil shows a sorption capacity of about 166 g/g. When applied to oil-floating-over-water, the Shola pith exhibits high selectivity for oil over water; almost all oil on the surface could be removed, leaving no trace of oil on the water surface. The Shola pith can also efficiently separate oil from an oil-in-water emulsion. This behavior is unprecedented in natural sorbents. The used material sorbs a considerable volume of the oil even after the 7th cycle. Furthermore about 95% of sorbed oil could be recovered from the material by solvent extraction. This study reveals for the first time some of the unique and interesting properties of Shola, a widely found biomass native to the eastern parts of the Indian subcontinent, and opens up possibilities of exploiting it for valuable applications.

1 aMondal, Keya1 aAdvani, Kushagra1 aGhosh, Snigdha1 aShanmugnathan, Kadhiravan1 aKulsi, Goutam1 aSivaram, Swaminathan1 aGupta, Sayam, Sen uhttps://library.ncl.res.in/content/shola-3d-porous-hydrophobic-oleophilic-lignocellulosic-material-efficient-oilwater