01916nas a2200229 4500008004100000022001400041245008700055210006900142260006800211300001200279490000800291520111000299653001501409653001801424653001701442653001601459100002301475700002001498700002801518700002701546856011301573 2007 eng d a0021-899500aDevelopment of transdermal drug-delivery films with castor-oil-based polyurethanes0 aDevelopment of transdermal drugdelivery films with castoroilbase a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcJAN a779-7880 v1033 a

Two different types of polyurethanes (PUs) were prepared with castor oil, ethylene glycol, isophorene diisocyanate and castor oil, and isophoren diisocyanate and poly(ethylene glycol) (400 or 600). PU films were prepared and characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and gel permeation chromatography. We prepared transdermal patches by loading different amounts of drug, plasticizer, and penetration enhancer. In vitro drug permeability through the castor-oil-based aliphatic PU patches was examined with a Keshary-Chien diffusion cell. The effect of castor oil on the film-forming properties and the effect of penetration enhancers on diffusion characteristics of indomethacin (IDM) drug through the castor-oil-based PU were investigated. Prolonged release of IDM was observed from the prepared PU patches. In vitro drug diffusion revealed that slow and prolonged release of IDM was achieved in the absence of penetration enhancers. The use of penetration enhancers showed a significant effect on drug diffusion. (c) 2006 Wiley Periodicals, Inc.

10acastor oil10adrug delivery10apolyurethane10atransdermal1 aShelke, Namdev, B.1 aSairam, Malladi1 aHalligudi, Shivaraj, B.1 aAminabhavi, Tejraj, M. uhttp://library.ncl.res.in/content/development-transdermal-drug-delivery-films-castor-oil-based-polyurethanes02306nas a2200205 4500008004100000022001400041245013300055210006900188260006800257300001400325490000800339520148100347653003401828653001901862653001501881653001701896100003101913700002501944856013101969 2010 eng d a0021-899500aInfluence of structure of organic modifiers and polyurethane on the clay dispersion in nanocomposites via in situ polymerization0 aInfluence of structure of organic modifiers and polyurethane on  a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcNOV a1774-17860 v1183 a

Influence of polyurethane (PU) structure on the nature of PU/clay nanocomposite was studied using varying amounts of trimethylol propane (TMP) as branching agent. The effect of hydroxyl groups in the modifier of organoclays on the structure of PU/clay nanocomposites was studied. Nanocomposites were characterized using wide-angle X-ray diffraction measurements (WAXD) and transmission electron microscopy (TEM). The results show that formation of completely exfoliated and well dispersed polyurethane/clay nanocomposites via in situ polymerization, is facilitated by the presence of tethering groups on the clay surface and an ability to form branched and crosslinked structures. Incorporation of long alkyl chains in addition to tethering hydroxyl groups in the modifier structure of the clay did not significantly improve the compatibility of linear PU with the clay. Intercalated thermoplastic polyurethane/clay nanocomposites, prepared using poly(caprolactone diol) as soft segment and isophorone diisocyanate and 1,4-butanediol as hard segments show increase in storage tensile moduli at temperatures before glass transition temperature when functional groups capable of chemically reacting with the growing polymer chains are present in the clay modifier. This is indicative of improved interaction of the polymer with the clay surface when the modifier has larger number of hydroxyl groups. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 1774-1786, 2010

10aintercalation and exfoliation10aNanocomposites10aorganoclay10apolyurethane1 aRama, Mallikarjuna, Shroff1 aSwaminathan, Sivaram uhttp://library.ncl.res.in/content/influence-structure-organic-modifiers-and-polyurethane-clay-dispersion-nanocomposites-situ-001797nas a2200217 4500008004100000022001400041245011000055210006900165260009200234300001400326490000700340520097200347653002101319653002001340653001501360653001701375100002001392700001901412700001901431856012901450 2010 eng d a1533-488000aSynthesis and characterization of polyurethane-grafted single-walled carbon nanotubes via click chemistry0 aSynthesis and characterization of polyurethanegrafted singlewall a26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USAbAMER SCIENTIFIC PUBLISHERScSEP a5700-57070 v103 a

Polyurethane (PU)-grafted carbon nanotubes were synthesized by the coupling of alkyne moiety decorated single walled carbon nanotube (SWCNT) with azide moiety containing PU using Cu(I) catalyzed Huisgen [3 + 2] cycloaddition click chemistry. The azide moiety containing poly(E-caprolactone)diol was synthesized by ring-opening polymerization and further used for PU synthesis. Alkyne-functionalizion of SWCNT was completed by the reaction of p-aminophenyl propargyl ether with SWCNT using a solvent free diazotization procedure. Nuclear magnetic resonance, Fourier transform infrared, and Raman spectroscopic measurements confirmed the functionalization of SWCNT. Scanning electron microscopy and transmission electron microscopy images showed an excellent dispersion of SWCNTs, and specially debundling of SWCNTs could be observed due to polymer assisted dispersion. A quantitative grafting was successfully achieved even at high content of functional groups.

10aCarbon nanotubes10aClick chemistry10adispersion10apolyurethane1 aRana, Sravendra1 aCho, Jae, Whan1 aKumar, Indresh uhttp://library.ncl.res.in/content/synthesis-and-characterization-polyurethane-grafted-single-walled-carbon-nanotubes-click-002342nas a2200241 4500008004100000022001400041245008200055210006900137260006700206300001200273490000700285520151200292653001401804653001701818653002601835653001701861653001301878100002601891700002401917700002101941700002501962856011301987 2015 eng d a0959-810300aPorous poly(ethylene glycol)-polyurethane hydrogels as potential biomaterials0 aPorous polyethylene glycolpolyurethane hydrogels as potential bi a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcMAR a397-4040 v643 a

We report the synthesis of porous poly(ethylene glycol)-polyurethane (PEG-PU) hydrogels using PEG-4000 as a soft segment and 4,4-methylenebis(cyclohexylisocyanate) as a hard segment. The degree of swelling in the hydrogels could be controlled by varying the amount of crosslinking agent, namely 1,2,6-hexanetriol. Structural characterization of the hydrogels was performed using solid-state C-13 NMR and Fourier transform infrared spectroscopy. Wide-angle X-ray diffraction studies revealed the existence of crystalline domains of PEG and small-angle X-ray scattering studies showed the presence of lamellar microstructures. For generating a porous structure in the hydrogels, cryogenic treatment with lyophilization was used. Scanning electron microscopy and three-dimensional micro-computed tomography imaging of the hydrogels indicated the presence of interconnected pores. The mechanical strength of the hydrogels and xerogels was measured using dynamic mechanical analysis. The observed dynamic storage moduli (E) for the equilibrium swollen and dry gels were found to be 0.15 and 4.2 MPa, respectively. Interestingly, the porous PEG-PU xerogel also showed E of 5.6 MPa indicating a similar mechanical strength upon incorporating porosity into the gel matrix. Finally, preliminary cytocompatibility studies showed the ability of cells to proliferate in the hydrogels. These gels show promise for applications as scaffolds and implants in tissue engineering. (c) 2014 Society of Chemical Industry

10ahydrogels10apermeability10apoly(ethylene glycol)10apolyurethane10aporosity1 aDivakaran, Anumon, V.1 aTorris, Arun, A. T.1 aLele, Ashish, K.1 aBadiger, Manohar, V. uhttp://library.ncl.res.in/content/porous-polyethylene-glycol-polyurethane-hydrogels-potential-biomaterials-001545nas a2200229 4500008004100000022001400041245008800055210006900143260000800212300001100220490000800231520076100239653003201000653002001032653002401052653001701076653002601093653002801119100002701147700002701174856011401201 2022 eng d a0021-899500aReinforcement of electrospun polyurethane fibers with resorcinol-formaldehyde resin0 aReinforcement of electrospun polyurethane fibers with resorcinol cMAY ae520070 v1393 a

This work reports a simple method to improve the properties of electrospun nanofibers. The procedure involves developing nanofibers using electrospinning followed by liquid infiltration to reinforce the fibers. Coating of polyurethane nanofibers (PUN) with resorcinol-formaldehyde (RF) significantly improves the properties of PUN. Furthermore, the morphology of fiber interface and the properties of RF coated fibers indicate that RF resin reinforces the interface between the fibers. The method leads to improvement in mechanical properties of PUN. An improvement of about 94% and 281% in mechanical properties like tensile strength and modulus, respectively, compared to neat PUN fibers is achieved by coating with 20% wt/vol of RF solution.

10aDynamic mechanical analysis10aelectrospinning10aliquid infiltration10apolyurethane10areinforced nanofibers10aresorcinol-formaldehyde1 aNair, Kiran, Sukumaran1 aJames, Nirmala, Rachel uhttp://library.ncl.res.in/content/reinforcement-electrospun-polyurethane-fibers-resorcinol-formaldehyde-resin01970nas a2200229 4500008004100000022001400041245007800055210006900133260000800202300001100210490000800221520123500229653001001464653001201474653002701486653001701513653002401530100003201554700001901586700002901605856010601634 2023 eng d a0926-860X00aSelective oxidation of 5-HMF to DFF over alkali promoted Mn nanocomposite0 aSelective oxidation of 5HMF to DFF over alkali promoted Mn nanoc cJUN a1191800 v6593 a

Various compositions of Cs promoted Mn catalysts were synthesized and investigated for selective oxidation of 5HMF to DFF, among which Mn-Cs(80:20) was found to be most efficient giving 91 % conversion of 5-HMF and 99 % selectivity to DFF. Detail characterization like N2-sorption, BET surface area, TG-DTA, XRD, XPS, FE-SEM-EDX, TEM, HR-TEM, CO2-TPD, H2-TPR, O2-TPO, FTIR, Raman spectra and CH3OH-IR were done to establish structureactivity correlation. Enhanced surface area, porosity, thermal stability, dual morphologies were observed due to inclusion of Cs in Mn lattice domain which further enhanced the crystallinity, and oxygen diffusion on the surface. Mixed morphologies comprising nanoparticles (4-5 nm) and nanocubes (50-60 nm) were observed with enhanced redox potential and reduced work function due to weakening of Mn-O bonds. Significant increase in the basicity of catalyst, interfacial redox properties and lattice oxygen led to highly efficient oxidation of 5-HMF to DFF via Mars-van Krevelen mechanism at relatively milder conditions i.e. T = 90 degrees C and PO2= 200 psig. The catalyst was easily recyclable up to 7 times with minor loss in activity which was regenerated heat treatment protocol.

10a5-HMF10aBiomass10aheterogeneous catalyst10apolyurethane10aSelective oxidation1 aSolanki, Bhanupratap, Singh1 aRoh, Hyun-Seog1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/selective-oxidation-5-hmf-dff-over-alkali-promoted-mn-nanocomposite