02214nas a2200277 4500008004100000022001400041245010600055210006900161260007700230300001200307490000800319520117400327653004101501653004501542653002301587653002801610653001301638100001901651700002101670700002301691700002301714700001501737700002801752700002501780856013101805 2005 eng d a1022-135200aHydrophobically modified poly(acrylic acid) using 3-pentadecylcyclohexylamine: synthesis and rheology0 aHydrophobically modified polyacrylic acid using 3pentadecylcyclo aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcFEB a464-4720 v2063 a

Hydrophobically modified poly(acrylic acid) was synthesized using 3-pentadecylcyclohexylamine (3-PDCA), which was in turn synthesized from 3-pentadecylphenol, one of the components of cashew-nut shell liquid (CNSL), a renewable resource material. H-1 NMR spectra confirmed the incorporation of 3-PDCA onto PAA and a series of HMPs with three different molar concentrations, viz. congruent to 3, 5 and 7 mol-% of 3-PDCA, were synthesized. An increase in viscosity with increasing hydrophobic content was observed by rheological measurements. The critical association concentrations were determined using an Ubbelohde viscometer and a controlled stress rheometer. The stability of HMPs towards temperature and shear was studied. Rheological measurements showed that there was a steady increase in viscosity with increase in hydrophobe content due to the formation of reversible networks. These polymers exhibited gel-like behavior at low concentrations (greater than or equal to2 wt.-%) with an apparent yield stress (ca. 10 Pa) and showed shear thinning properties (non-Newtonian). However, below a critical concentration, c [eta], they showed Newtonian behavior.

10a3-pentadecylcyclohexylamine (3-PDCA)10ahydrophobically modified polymers (HMPs)10apoly(acrylic acid)10areversible associations10aRheology1 aShedge, A., S.1 aLele, Ashish, K.1 aWadgaonkar, P., P.1 aHourdet, Dominique1 aPcrrin, P.1 aChassenieux, Christophe1 aBadiger, Manohar, V. uhttps://library.ncl.res.in/content/hydrophobically-modified-polyacrylic-acid-using-3-pentadecylcyclohexylamine-synthesis-and-102205nas a2200205 4500008004100000022001400041245003400055210003400089260009900123300001200222490000700234520159000241653001901831653001301850653001401863100001701877700001601894700002101910856006801931 2006 eng d a0260-877400aStudies on shrikhand rheology0 aStudies on shrikhand rheology aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcMAY a169-1770 v743 a

Shrikhand, a popular Indian dessert made from yogurt, is manufactured on an industrial scale using several chemical engineering unit operations such as mixing, filtration and heat transfer. Understanding the rheology of shrikhand is not only relevant for designing large scale mixers but can also provide quantitative means for linking the microstructure of shrikhand to its perception of texture, consistency and taste. We show here that shrikhand exhibits a combination of several rheological properties such as weak gel-like viscoelasticity, an apparent yield stress, thixotropy and long structural recovery time scales. For instance, the elastic modulus is always higher than the loss modulus over the measurable frequency range and that both moduli show only weak frequency dependence that is a characteristic of gel-like consistency. Forward and reverse rate sweep tests show a distinct hysteresis loop, which is a signature of thixotropic character. In an attempt to trace the origins of these rheological properties in shrikhand we characterized its microstructure and showed that there exist two different microstructures: one composed of crystallites of milk fats having a length scale of similar to 50-100 mu m, and the other composed of aggregates of colloidal cascin micelles of similar to 0.5-10 mu m size. Our studies show that while the temperature sensitivity of the viscoelastic parameters is dominated by the semicrystalline milk fat microstructure, the shear sensitivity is largely dictated by the protein network. (c) 2005 Elsevier Ltd. All rights reserved.

10aMicrostructure10aRheology10ashrikhand1 aKulkarni, C.1 aBelsare, N.1 aLele, Ashish, K. uhttps://library.ncl.res.in/content/studies-shrikhand-rheology-001589nas a2200289 4500008004100000020002200041022001400063245004500077210004500122260010600167300001200273490000900285520068300294653002900977653001301006653002101019100002401040700002101064700002801085700001801113700002201131700001101153700001701164700001801181700002101199856007901220 2008 eng d a978-0-7354-0549-3 a0094-243X00aGelation of regenerated fibroin solution0 aGelation of regenerated fibroin solution aMonterey, CA.bAmer Inst Physics, 2 Huntington Quadrangle, STE 1NO1, Melville, NY 11747-4501 USAcAUG a573-5750 v10273 a

Silk fibroin is a high molecular weight multiblock ampiphillic protein known for its ability to form high strength fibers. It is also biocompatible; silk sutures have been traditionally used for many centuries. Recently, there has been much interest in making silk hydrogels for applications ranging from tissue engineering to controlled delivery. Fibroin gels can be formed from aqueous solutions by changing one or more state variables such as pH, temperature and ionic strength. In this work we present our investigations on the gelation of aqueous fibroin solutions derived from Bombyx Mori silk using light scattering, confocal microscopy and rheological techniques.

10adynamic light scattering10aRheology10asilk fibroin gel1 aNagarkara, Shailesh1 aLele, Ashish, K.1 aChassenieux, Christophe1 aNicolai, Taco1 aDurand, Dominique1 aCo, A.1 aLeal, L., G.1 aColby, R., H.1 aGiacomin, A., J. uhttps://library.ncl.res.in/content/gelation-regenerated-fibroin-solution-101937nas a2200229 4500008004100000022001400041245006000055210005700115260006800172300001400240490000800254520118200262653001801444653002301462653001301485653003301498653002301531100002101554700002101575700002401596856008701620 2009 eng d a0021-899500aReactive extrusion of poly(L-Lactic Acid) with glycidol0 aReactive extrusion of polyLLactic Acid with glycidol a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcMAY a1391-13980 v1123 a

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'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'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'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

10abiodegradable10areactive extrusion10aRheology10astructure-property relations10aThermal properties1 aDeenadayalan, E.1 aLele, Ashish, K.1 aBalasubramanian, M. uhttps://library.ncl.res.in/content/reactive-extrusion-polyl-lactic-acid-glycidol-002613nas a2200229 4500008004100000022001400041245011300055210006900168260006800237300001400305490000700319520173200326653001602058653004902074653001302123653002702136100002202163700002802185700002102213700002502234856012402259 2010 eng d a0887-626600aHydrophobically modified poly(vinyl alcohol) using alkoxy-substituted methyl gallate: synthesis and rheology0 aHydrophobically modified polyvinyl alcohol using alkoxysubstitut a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcMAY a1054-10630 v483 a

Hydrophobically modified poly(vinyl alcohol) (HMPVA) polymers were synthesized by potassium t-butoxide-catalyzed reaction of PVA with methyl 3,4,5-tris(n-octyloxy) benzoate (MGC(8))/3,4,5-tris(n-dodecyloxy) benzoate (MGC(12)) and 1,3-propane sultone. The concentration of 1,3-propane sultone was kept constant at 10 mol %. and that of MGC(8) (2, 3, and 4 mol %)/MGC(12) (2 and 3 mol %) was varied to obtain HMPVAs with different hydrophobic contents. The incorporation of MGC(8)/MGC(12) and 1,3-propane sultone onto HMPVA was confirmed by NMR spectroscopy. Rheological properties of aqueous solutions also confirmed the presence of hydrophobic and charged functional groups on HMPVAs. In the semidilute regime, the specific viscosity of HMPVAs followed concentration scaling that is typical of polyelectrolytes. At higher concentrations, the HMPVA solutions with 3 and 4 mol % of MGC(8) exhibited large increase in specific viscosity. Oscillatory experiments on these solutions exhibited gel-like behavior at polymer concentrations of 40-50 g/L. Confocal microscopy images of HMPVA with 4 mol % of MGC(8) clearly indicated the existence of microgels. The tendency of formation of microgels further increased with increasing chain length of the hydrophobe, that is, with MGC(12). These samples exhibited rheological behavior that is typical of soft solids and was therefore probed by the strain-rate frequency superposition technique reported recently in the literature. HMPVAs with improved rheological properties show potential applications as thickeners in cosmetic creams, lotions and as drug carriers in pharmaceutical formulations. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1054-1063, 2010

10agallic acid10ahydrophobically modified poly(vinyl alcohol)10aRheology10awater-soluble polymers1 aShedge, Aarti, S.1 aWadgaonkar, Prakash, P.1 aLele, Ashish, K.1 aBadiger, Manohar, V. uhttps://library.ncl.res.in/content/hydrophobically-modified-polyvinyl-alcohol-using-alkoxy-substituted-methyl-gallate-002507nas a2200265 4500008004100000022001400041245010100055210006900156260007600225300001400301490000700315520155300322653002201875653003001897653001901927653001801946653001301964653003201977100002202009700002202031700002002053700002402073700002002097856012402117 2011 eng d a0959-810300aInfluence of reactive compatibilization on the structure and properties of PP/LDH nanocomposites0 aInfluence of reactive compatibilization on the structure and pro aCOMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USAbWILEY-BLACKWELLcDEC a1688-16960 v603 a

Polypropylene (PP)/layered double hydroxide (LDH) nanocomposites were prepared by the direct melt intercalation method usingmaleic anhydride grafted polypropylene (PP-g-MAH) as a reactive compatibilizer. The compatibilization effects provided by PP-g-MAH in different weight fractions and their influence on the structure and properties of the final nanocomposites were investigated. The interactions and structural morphology of the nanocomposites were examined by Fourier transform infrared spectroscopy, X-ray diffraction and transmission electronmicroscopy. Thermal, mechanical and rheological properties of these nanocomposites were investigated as a function of compatibilizer concentration. The detailed morphological and X-ray diffraction results revealed that the degree of LDH dispersion increases as the amount of PP-g-MAH increases. Study of the linear viscoelastic properties showed that the storage modulus G' is very sensitive to the microstructure of the nanocomposite. The thermal properties of the nanocomposites were significantly influenced by the weight fraction of PP-g-MAH due to the shielding and nucleating effect of exfoliated layers. Both the tensile strength and modulus showed substantial improvements with increasing PP-g-MAH content, while the elongation at break substantially decreased, although the presence of PP-gMAH somewhat improves these values. The overall results showed that 10 wt% of compatibilizer is optimum to achieve nanocomposites with better performance. (C) 2011 Society of Chemical Industry

10acompatibilization10alayered double hydroxides10aNanocomposites10apolypropylene10aRheology10athermomechanical properties1 aLonkar, Sunil, P.1 aTherias, Sandrine1 aLeroux, Fabrice1 aGardette, Jean, Luc1 aSingh, Raj, Pal uhttps://library.ncl.res.in/content/influence-reactive-compatibilization-structure-and-properties-ppldh-nanocomposites-002008nas a2200229 4500008004100000022001400041245016100055210006900216260011700285300001000402490000600412520109600418653001501514653001901529653001901548653001401567653001301581653001601594100002401610700002101634856012301655 2012 eng d a0973-626300aGellan Gum a novel polysaccharide matrix for immobilization of thermo-tolerant yeast cells with invertase activity: factorial design and rheological studies0 aGellan Gum a novel polysaccharide matrix for immobilization of t aSECTOR A-80, SCHEME NO 54, VIJAY NAGAR, A B ROAD, INDORE, 452 010 MP, INDIAbRESEARCH JOURNAL BIOTECHNOLOGYcNOV a81-870 v73 a

The microbial extracellular polysaccharide gellan gum has been explored for its application in whole cell immobilization. Preliminary evaluation of the physicochemical properties of gellan gum in the presence of monovalent cation tetramethyl ammonium chloride (TMACl) was carried out. Gellan gum immobilized cells demonstrated better rheological properties than gellan gum. Attempts have been made to reveal the evaluation of gellan gum as a matrix to immobilize a thermotolerant yeast Kluyveromyces marxianus NCYC 2675. A 3(2) factorial design was used to study the simultaneous effect of two variables. The effect of the polymer concentration and TMACl concentration on various dependent variables like gelling temperature, mean particle size and enzyme activity of the yeast cells was studied. A statistical model with a significant interaction term was obtained to predict the results. Further, optimized immobilized system was evaluated with significant storage stability at 10 C and enhanced reusability with maximum conversion of > 90 % when crosslinked with glutaraldehyde.

10aGellan gum10aGlutaraldehyde10aImmobilization10ainvertase10aRheology10ayeast cells1 aSulabha, Karandikar1 aAsmita, Prabhune uhttps://library.ncl.res.in/content/gellan-gum-novel-polysaccharide-matrix-immobilization-thermo-tolerant-yeast-cells-002046nas a2200265 4500008004100000022001400041245006600055210006600121260005700187300001200244490000700256520123100263653002601494653002001520653000901540653001201549653001401561653001301575653001301588100002201601700001901623700002001642700002101662856009701683 2013 eng d a0035-451100aAscertaining universal features of yielding of soft materials0 aAscertaining universal features of yielding of soft materials a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcNOV a859-8650 v523 a

Many metastable complex fluids, when subjected to oscillatory shear flow of increasing strain amplitude at constant frequency, are known to show a characteristic nonlinear rheological response which consists of a monotonic decrease in the elastic modulus and a nonmonotonic change in the loss modulus. In particular, the loss modulus increases from its low strain value, crosses the elastic modulus, and then decreases with further increase in the strain amplitude. Miyazaki et al. (Europhys Lett 75:915-921, 2006) proposed a qualitative argument to explain the origin of the nonmonotonic nature of the loss modulus and suggested that in fact this response could be universal to all complex fluids if they are probed in a certain frequency window in which the fluid is dominantly elastic in the small strain limit. In this letter, we confirm their hypothesis by showing that a wide variety of complex fluids, irrespective of their thermodynamic state under quiescent conditions, indeed show the aforementioned characteristic nonlinear response. We also show that the maximum relative dissipation during yielding occurs when the imposed frequency resonates with the characteristic beta relaxation frequency of the fluid.

10aColloidal suspensions10aEntangled melts10aGels10aGlasses10aMicrogels10aRheology10aYielding1 aKamble, Samruddhi1 aPandey, Anurag1 aRastogi, Sanjay1 aLele, Ashish, K. uhttps://library.ncl.res.in/content/ascertaining-universal-features-yielding-soft-materials-001568nas a2200229 4500008004100000022001400041245007900055210006900134260005700203300001200260490000700272520079800279653002501077653001801102653001301120653000901133100001701142700002101159700002401180700002101204856011301225 2013 eng d a0035-451100aRheology and microstructural studies of regenerated silk fibroin solutions0 aRheology and microstructural studies of regenerated silk fibroin a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcNOV a833-8400 v523 a

Regenerated silk fibroin solutions (RSF) are produced by dissolving degummed silk fibers in water. We have observed that RSF solutions at a concentration less than 15 % by weight exhibit an unusual gel-like response in conventional shear rheology measurements. At higher concentrations, the response is predominantly viscous (or liquid-like). We have probed this counterintuitive behavior of silk fibroin solutions by using microrheology, and interfacial rheometry. Scattering techniques were also used to understand the microstructure of RSF solutions as a function of the concentration. Our studies suggest that the gel-like response of the RSF solution may result from the formation of an interfacial film at the air-solution interface, which dominates the bulk rheological response.

10aInterfacial rheology10aMicrorheology10aRheology10aSilk1 aNisal, Anuya1 aKalelkar, Chirag1 aBellare, Jayesh, R.1 aLele, Ashish, K. uhttps://library.ncl.res.in/content/rheology-and-microstructural-studies-regenerated-silk-fibroin-solutions-002489nas a2200301 4500008004100000022001400041245013200055210006900187260009900256300001200355490000800367520135800375653002301733653002701756653001401783653001301797653002201810653003201832100002201864700002401886700002801910700002401938700002301962700002301985700002302008700002502031856013102056 2015 eng d a0144-861700aSynthesis and characterization of PEPO grafted carboxymethyl guar and carboxymethyl tamarind as new thermo-associating polymers0 aSynthesis and characterization of PEPO grafted carboxymethyl gua aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcMAR a331-3380 v1173 a

New thermo associating polymers were designed and synthesized by grafting amino terminated poly(ethylene oxide-co-propylene oxide) (PEPO) onto carboxymethyl guar (CMG) and carboxymethyl tamarind (CMT). The grafting was performed by coupling reaction between-NH2 groups of PEPO and -COOH groups of CMG and CMT using water-soluble EDC/NHS as coupling agents. The grafting efficiency and the temperature of thermo-association, T-assoc in the copolymer were studied by NMR spectroscopy. The graft copolymers, CMG-g-PEPO and CMT-g-PEPO exhibited interesting thermo-associating behavior which was evidenced by the detailed rheological and fluorescence measurements. The visco-elastic properties (storage modulus, G'; loss modulus, G'') of the copolymer solutions were investigated using oscillatory shear experiments. The influence of salt and surfactant on the T-assoc was also studied by rheology, where the phenomenon of ``Salting out'' and ``Salting in'' was observed for salt and surfactant, respectively, which can give an easy access to tunable properties of these copolymers. These thermo-associating polymers with biodegradable nature of CMG and CMT can have potential applications as smart injectables in controlled release technology and as thickeners in cosmetics and pharmaceutical formulations. (C) 2014 Elsevier Ltd. All rights reserved.

10aCarboxymethyl guar10aCarboxymethyl tamarind10aPluronics10aRheology10aSolution behavior10aThermo-associating polymers1 aGupta, Nivika, R.1 aTorris, Arun, A. T.1 aWadgaonkar, Prakash, P.1 aRajamohanan, P., R.1 aDucouret, Guylaine1 aHourdet, Dominique1 aCreton, Costantino1 aBadiger, Manohar, V. uhttps://library.ncl.res.in/content/synthesis-and-characterization-pepo-grafted-carboxymethyl-guar-and-carboxymethyl-tamarind-102042nas a2200277 4500008004100000022001100041245009300052210006900145260000800214300001200222490000800234520107600242653004901318653002101367653007401388653001301462653002001475100001701495700001801512700001801530700002101548700002601569700002401595700002501619856012001644 2018 eng d a32386100aThermo thickening behavior of MPEG-b-PCL grafted poly(acrylic acid): a molecular insight0 aThermo thickening behavior of MPEGbPCL grafted polyacrylic acid  cJUL a138-1480 v1483 a

We report on the synthesis and characterization of a new thermothickening polymer (PAA-g-(MPEG-b-PCL)) based on the grafting of a block copolymer of mono methoxy poly (ethylene glycol)–b-poly (caprolactone) (MPEG-b-PCL) onto poly (acrylic acid) (PAA). Rheological experiments reveal that aqueous solutions of PAA-g-(MPEG-b-PCL) exhibit interesting irreversible thermothickening behavior above a certain polymer concentration and critical temperature. Light scattering experiments show that increasing temperature induces hydrophobic associations and subsequent aggregation leading to gel formation which is irreversible. The mechanism of thermo thickening was examined at the molecular level by NMR methods which indicated unassembled and assembled environments of the MPEG-b-PCL grafts. On heating, interactions between the graft side chains are significantly enhanced and molecular mobility in the assembled microdomains is reduced. The stable well ordered microdomains that are formed on heating are retained on cooling thus, leading to irreversible gelation.

10aHydrophobically modified poly (acrylic acid)10aLight scattering10aMethoxy polyethylene glycol-b-polycaprolactone (MPEG-b-PCL) copolymer10aRheology10aThermo gelation1 aTiwari, Neha1 aShedge, Aarti1 aFayis, K., P.1 aBhat, Suresh, K.1 aRavindranathan, Sapna1 aRajamohanan, P., R.1 aBadiger, Manohar, V. uhttps://library.ncl.res.in/content/thermo-thickening-behavior-mpeg-b-pcl-grafted-polyacrylic-acid-molecular-insight02272nas a2200253 4500008004100000022001400041245006300055210006300118260000800181300001200189490000700201520153700208653002001745653001501765653000801780653001901788653001301807653001701820100002101837700002301858700002101881700002101902856009501923 2020 eng d a0035-451100aMicrostructure and yielding of capillary force induced gel0 aMicrostructure and yielding of capillary force induced gel cMAY a291-3060 v593 a

We have investigated the rheology and structure of a gel formed from a mixture of non-Brownian particles and two immiscible liquids. The suspension of particles in a liquid undergoes gelation upon the addition of a small content of second, wetting liquid which forms liquid bridges between particles leading to a sample spanning network. The rheology of this gel primarily exhibits a yield stress at low shear rates followed by a linear variation of shear stress at high shear rates. The apparent yield stress extracted from the flow curves increases rapidly with volume fraction of the second liquid before saturation, while it exhibits a monotonic increase with increasing particle concentration. Rescaling of the yield stress curves using suitable shift factors results in an empirical expression for the yield stress showing squared dependence on liquid fraction and a rapid increase with particle fraction above a certain value, both combined in a highly non-linear manner. The microstructural variations with changing secondary liquid content and particle fractions are captured using three-dimensional X-ray tomography technique. The microstructure is observed to show increased local compactness with increased liquid content and increased spatial homogeneity with increased particle fractions. The images from X-ray tomography are analysed to obtain the distributions of particle-particle bonds (coordination number) in the system which serve to explain the observed yield stress behaviour in a qualitative manner.

10aCapillary force10aFlow curve10agel10aMicrostructure10aRheology10aYield stress1 aHuprikar, Sameer1 aUsgaonkar, Saurabh1 aLele, Ashish, K.1 aOrpe, Ashish, V. uhttps://library.ncl.res.in/content/microstructure-and-yielding-capillary-force-induced-gel02609nas a2200337 4500008004100000022001400041245017500055210006900230260000800299300002100307490000700328520146600335653001901801653003301820653001401853653000901867653003001876653001301906653001901919653001701938653001301955653001401968100002201982700002102004700002002025700002902045700002502074700002302099700001802122856013102140 2021 eng d a8756-087900aControlling draw resonance during extrusion film casting of nanoclay filled linear low-density polyethylene: an experimental study and numerical linear stability analysis0 aControlling draw resonance during extrusion film casting of nano cJUL a87560879209784430 v373 a

Commercially important extrusion film casting (EFC) processes for manufacturing plastic films or sheets are hampered by several instabilities that severely limits their productivity. In this research we focussed on one important instability: the draw resonance that occurs during the EFC process mainly under extensional flow conditions. Draw resonance is the sustained periodic oscillations in the film dimensions, notably film width and thickness, when the process operates beyond a critical draw ratio (CDR). In this research our goal was to reduce this draw resonance instability by incorporating well dispersed nanoclay fillers in a base polymeric resin (such as a linear low density polyethylene - LLDPE) to determine how these nanocomposite (NC) formulations can prevent or reduce the draw resonance defect. EFC experiments were conducted on the base resin and on the NC formulations under non-isothermal conditions to determine the onset of the draw resonance experimentally. Conventional linear stability analysis was performed to determine the onset of the draw resonance defect numerically. Numerical predictions for the onset of draw resonance were in qualitative agreement with our experimental data. Our results showed that incorporating appropriate nanoclay concentrations in a base polymeric resin indeed enhanced the EFC process stability for those polymer formulations and thus can have important economic implications for processors.

10aDraw resonance10aextensional strain hardening10aExtrusion10aFilm10ahydrodynamic interactions10aNanoclay10aNanocomposites10aPolyethylene10aRheology10astability1 aRokade, Dhammaraj1 aChougale, Sanket1 aPatil, Prashant1 aBhattacharjee, Tanushree1 aGawande, Dnyaneshwar1 aPol, Harshawardhan1 aDhadwal, Renu uhttps://library.ncl.res.in/content/controlling-draw-resonance-during-extrusion-film-casting-nanoclay-filled-linear-low-density02178nas a2200241 4500008004100000022001400041245011600055210006900171260000800240300001200248490000700260520139300267653001201660653001301672653001401685653002001699653001301719100002301732700001801755700002101773700001801794856012401812 2021 eng d a0959-810300aInjectabledextran-fluorenylmethoxycarbonylphenylalanine composite hydrogels with improved mechanical properties0 aInjectabledextranfluorenylmethoxycarbonylphenylalanine composite cFEB a222-2290 v703 a

Low molecular weight hydrogels are recently gaining importance owing to their applications in material sciences and biology. A new class of composite hydrogel was developed using polysaccharides such as dextran and fluorenylmethoxycarbonyl phenylalanine (FmocF) in a phosphate buffer. The molecular weight and concentration of the dextran were varied to obtain rigid but injectable hydrogels without using other crosslinking agents. From the different molecular weights of dextran studied (5k, 40k and 70k), a combination of FmocF (0.6% w/v) and dextran 40k (0.012% w/v) composite gels yielded a maximum value of storage modulus of approximately 1500 Pa, which is 3.5 times higher than the storage modulus of pure FmocF gels. Scanning electron microscopy of FmocF/dextran composite gels revealed highly tangled fibrous structures with dense branches and lower fiber diameter compared to pure FmocF gels. The high-intensity hydrogen-bonded N-H peak in the infrared spectra showed enhanced hydrogen bonding in FmocF/dextran composite gels compared to pure FmocF gels. The dextran acts as an impurity in the process of fibrillation, leading to a crystallographic mismatch, and densely packed thin fibers are formed. These gels exhibited gel to sol and sol to gel conversion with temperature or external stress and showed injectable behavior. (c) 2020 Society of Industrial Chemistry

10aDextran10aFmoc-Phe10ahydrogels10ainjectable gels10aRheology1 aAbraham, Jancy, N.1 aJoseph, Seena1 aTrivedi, Rishabh1 aKarle, Mrunal uhttps://library.ncl.res.in/content/injectabledextran-fluorenylmethoxycarbonylphenylalanine-composite-hydrogels-improved01933nas a2200253 4500008004100000022001400041245014900055210006900204260000800273300001200281490000700293520097800300653002501278653003801303653002601341653001301367653002301380653003001403100001701433700003001450700004301480700002601523856013001549 2022 eng d a0959-810300aInvestigation of domain structures in monomethoxy poly(ethylene glycol)-b-poly(caprolactone) grafted poly(acrylic acid) by NMR diffusion studies0 aInvestigation of domain structures in monomethoxy polyethylene g cAUG a976-9840 v713 a

Associating polymers developed by grafting a block copolymer of monomethoxy poly(ethylene glycol)-b-poly(caprolactone) (MPEG-b-PCL) onto poly(acrylic acid) undergo an irreversible sol-gel transition on heating. The influence of various physicochemical parameters on the thermoresponsive behaviour was examined by rheology and NMR studies. Pulsed field gradient NMR diffusion studies were performed to probe the mechanism of thermally induced gelation. Analysis of the diffusion data reveals the presence of loosely and strongly associated structures which respond differently to variation in temperature. It is observed that the polymer solution, which is visibly homogeneous, is heterogeneous on a mesoscopic scale with a distribution of domains. Detailed investigation of the thermally induced sol-gel transition shows that the mechanism of gelation involves irreversible alterations in the domain structure and size. (c) 2022 Society of Industrial Chemistry.

10aassociating polymers10ahydrophobically modified polymers10aNMR diffusion studies10aRheology10asol-gel transition10athermoresponsive polymers1 aTiwari, Neha1 aBadiger, Manohar, Virupax1 aRajamohanan, Pattuparambil, Ramanpilla1 aRavindranathan, Sapna uhttps://library.ncl.res.in/content/investigation-domain-structures-monomethoxy-polyethylene-glycol-b-polycaprolactone-grafted02508nas a2200253 4500008004100000022001400041245012300055210006900178260000800247300001100255490000700266520164100273653002201914653002601936653002101962653002601983653001302009653001602022100001902038700001802057700002402075700003102099856012402130 2023 eng d a0969-023900aSynthesis of N-oxyethylene substituted imidazolium-based zwitterions as a recyclable solvent for cellulose dissolution0 aSynthesis of Noxyethylene substituted imidazoliumbased zwitterio cJAN a87-1090 v303 a

Cellulose is a readily available, renewable, and natural biomaterial that has the potential to replace synthetic fibres. However, their processing to shaped materials such as fibre or film is still complex and restricted due to its insolubility in most conventional solvents. Herein, we present the synthesis and cellulose dissolution characteristics of a new class of recyclable zwitterions composed of tethered N-oxyethylene substituted imidazolium cation and alkyl carboxylate anion. Investigations on cellulose dissolution showed that increasing the alkyl chain length of carboxylate anion and introduction of oxyethylene unit on imidazolium ring led to better cellulose dissolution ability, and up to 12% (w/w) cellulose could be dissolved in aqueous zwitterions at 105 degrees C. The thermal behavior of zwitterions and their cellulose solutions was characterized by TGA and found to be more stable than the NMMO and Lyocell solutions. Rheological characterization of cellulose solutions revealed viscoelastic behavior and zero shear viscosity of 6-12% (w/w) cellulose solution in hexanoate containing aqueous zwitterion was 555 to 5900 Pa.s at 120 degrees C. The characteristics of cellulose solution indicate its potential for processing to cellulose fibre by extrusion through a tiny spinneret. Physico-chemical analysis of regenerated cellulose indicates that zwitterions cause no adverse effect on cellulose structure and morphology during dissolution. The zwitterions are recovered after the cellulose regeneration process, and the recovery was found to be 99.6% after purification using the ion-exchange method.

10aCarboxylate anion10aCellulose dissolution10aOxyethylene unit10aRegenerated cellulose10aRheology10azwitterions1 aJadhav, Sachin1 aGanvir, Vivek1 aSingh, Madan, Kumar1 aShanmuganathan, Kadhiravan uhttps://library.ncl.res.in/content/synthesis-n-oxyethylene-substituted-imidazolium-based-zwitterions-recyclable-solvent