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Soluble Polymers (soluble + polymer)
Selected AbstractsEfficient Biocatalytic Cleavage and Recovery of Organic Substrates Supported on Soluble PolymersADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2007Dario Pasini Abstract The applicability of novel solution-phase supports in combination with enzymes for biocatalytic transformations is reported. Ex novo designed styrene-based copolymers, bearing a phenylacetic residue in variable loadings and linked as a pendant group to the macromolecular backbone, through a spacer of variable length, have been synthesized and characterized. These derivatives are compatible and can be used as soluble supports in combination with immobilized penicillin G acylase (PGA , EC 3.5.1.11) for the biocatalytic cleavage of the covalently anchored organic substrate in quantitative yields, in water or water/dimethylformamide solvent mixtures, with recovery of the immobilized enzyme with negligible losses in activity. [source] Using polymers to control substrate, ligand, or catalyst solubilityJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 14 2001David E. Bergbreiter Abstract The attributes and design of soluble polymer supports for catalysis and synthesis are discussed. By manipulating polymer structure, polymer supports can be prepared so that the solubility of an attached reagent, substrate, or ligand is affected by heating, cooling, pH, or solvent identity. Supports with such engineered solubility are useful both in organic synthesis and catalysis. They can be used as purification handles in organic synthesis as a way to recover catalysts, as a way to turn reactions on or off, and more generally, as a handle for separations. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2351,2363, 2001 [source] A Solid-State Organic Electronic Wettability Switch,ADVANCED MATERIALS, Issue 4 2004J. Isaksson Solid-state devices based on soluble polymers on a rigid substrate, with the active surface facing the environment, have been designed and characterized. The contact angles and spreading of water droplets can be reversibly controlled by electrochemically reducing or oxidizing a polymer surface (see Figure). [source] The Immobilization of Rhodium-4-(diphenylphosphino)-2- (diphenylphosphinomethyl)-pyrrolidine (Rh-PPM) Complexes: A Systematic StudyADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 12-13 2006Benoît Pugin Abstract A modular toolbox for the immobilization of homogeneous catalysts to various supports is described. It consists of functionalized chiral diphosphines and three different linkers based on isocyanate chemistry and it is used to attach the 4-(diphenylphosphino)-2-(diphenylphosphinomethyl)-pyrrolidine (PPM) ligand to a large variety of soluble, swellable and non-swellable solid organic polymers and to silica gels. As model reaction the hydrogenation of acetamidocinnamic acid derivatives, catalyzed with high enantioselectivity was chosen. Besides information on the usefulness of a particular type of support for synthetic applications, the experiments were also designed to address the question how parameters such as solubility, swellability, cage or pore size and solvent affect the rate and enantioselectivity of an immobilized catalyst. Rhodium complexes of ligands attached to soluble polymers and inorganic supports achieved ees up to 95,% and turnover frequencies between 700 and 1400,h,1, very close to the values of the homogeneous Rh catalyst (ee 95,%, TOF 1320,h,1). Insoluble or strongly cross-linked organic polymers led to catalysts with lower enantioselectivity and activity. PPM ligands attached to water soluble dendrimer fragments allowed hydrogenation in water solution with ees up to 94,%, albeit with much lower activity compared to reactions in methanol with the homogeneous catalyst. [source] The effect of water-soluble polymers on rheology of microfibrillar cellulose suspension and dynamic mechanical properties of paper sheetJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Arja-Helena Vesterinen Abstract Rheological properties of fiber/polymer suspensions and dynamic mechanical analysis (DMA) of paper sheets containing the same polymers were measured. Correlations between viscoelastic properties of suspensions and strength of paper sheet are presented. Rheological properties of suspensions of microfibrillar cellulose (MFC) and a set of water soluble polymers were measured. Rheological properties of these complex fluids vary considerably depending on the added polymer. A suspension of fiber and carboxymethyl cellulose (CMC) exhibits a viscosity higher than the sum of the viscosity of the individual components in the suspension. In contrast, when cationic starch (CS) is used together with the fiber, the yielding behavior rather than the viscosity is characteristic of the suspension. Dynamic mechanical properties of paper sheets containing CMC or CS as additives were studied at different humidity levels. Different yielding behavior observed in oscillatory rheology can be correlated with straining behavior in dynamic mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Synthesis and enantioselectivities of soluble polymers incorporating optically active binaphthyl and binaphtholJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2007Xiaowei Zou Abstract A polymer (P-1) was synthesized through the polymerization of (S)-6,6,-dibromo-3,3,-dibutyl-1,1,-binaphthol with (S)-2,2,-dioctoxy-1,1,-binaphthyl-6,6,-boronic acid in a Pd-catalyzed Suzuki reaction, and another polymer (P-2) was synthesized through the polymerization of (S)-6,6,-dibromo-3,3,-dibutyl-1,1,-binaphthol with (S)-6,6,-diethynyl-2,2,-dioctoxy-1,1,-binaphthyl in a Pd-catalyzed Sonogashira reaction. The two polymers showed good solubility in some common solvents and were characterized with NMR, Fourier transform infrared, gel permeation chromatography, and circular dichroism spectroscopy. The application of the chiral monomers and polymers in the asymmetric addition of diethyl zinc to benzaldehyde was studied. The results indicated that P-1, P-2, and the monomer (S)-3,3,-dibutyl-1,1,-binaphthol were efficient ligands in the asymmetric addition of diethyl zinc to benzaldehyde. The chiral polymer ligands P-1 and P-2 were more efficient than their monomeric version, (S)-3,3,-dibutyl-1,1,-binaphthol, and could be easily recovered and reused without a loss of catalytic activity or enantioselectivity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 [source] Compaction of pharmaceutical tablets with different polymer matrices studied by FTIR imaging and X-ray microtomographyJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 10 2008Patrick Wray Abstract Water soluble polymers are often used in tablet compaction for their desirable compaction and dissolution properties. ATR-FTIR spectroscopic imaging has been used to analyze in situ the spatial distribution of different components in tablets with different compositions. Caffeine tablets made of three different polymer matrices, microcrystalline cellulose, hydroxypropyl methylcellulose (HPMC) and lactose, were investigated. It was found that the distribution of caffeine is strongly affected by the composition of polymer matrix used in the tablet. X-ray tomography was used to analyze the caffeine distribution as a complementary technique. The results obtained were compared to the ATR-FTIR spectroscopic images. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:4269,4277, 2008 [source] Synthesis of imidazole-containing conjugated polymers bearing phenol unit as side group and excited state intramolecular proton transfer-mediated fluorescenceJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 18 2009Koji Takagi Abstract Dibromobenzimidazole and dibromoimidazole bearing hydroxyl group-protected phenol unit (1 and 2) were prepared and they showed an intramolecular hydrogen bonding between ether oxygen and amino proton of imidazole. The palladium-catalyzed Suzuki coupling polymerization of 1 and 2 with benzene bis(boronic acid) derivatives gave soluble polymers (3 and 4), where the molecular weights were limited probably due to the coordination ability of imidazole to palladium metal. The phenol hydroxyl groups were subsequently deprotected using BBr3 to obtain 3, and 4,. From the 1H NMR spectra, the complete conversion to the hydroxyl group and the formation of another type of intramolecular hydrogen bonding between hydroxyl proton and imine nitrogen were confirmed. In the UV and PL spectra of 3, and 4,, the excited state intramolecular proton transfer (ESIPT) occurred to shift the emission spectra toward lower energy region compared to 3 and 4. Especially, the PL spectrum of 3, demonstrated large stokes shift (145 nm) in THF solution. The ESIPT-mediated fluorescence was influenced by the addition of methanol and trifluoroacetic acid, which inhibited the formation of intramolecular hydrogen bonding. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4822,4829, 2009 [source] Synthesis and liquid crystalline properties of poly(1-alkyne)s carrying triphenylene discogensJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 9 2008Changmin Xing Abstract Triphenylene-containing 1-decynes with different alkyl chain lengths and their polymers are synthesized and the effects of the structural variables on their mesomorphic properties are investigated. The monomers [HCC(CH2)8CO2C18H6 (OCmH2m+1)5; m = 4,9] are prepared by consecutive etherization, coupling, and esterification reactions. The monomers form columnar phases at room temperature. The polymerizations of the monomers are effected by [Rh(nbd)Cl]2, producing soluble polymers in high yields (up to 84%). The structures and properties of the polymers are characterized and evaluated by IR, NMR, TGA, DSC, POM, and XRD analyses. All the polymers are thermally stable, losing little of their weights when heated to 300 °C. The isotropization temperature of the polymers increases initially with the length of alkyl chain but decreases on further extension. Although the polymers with shorter and longer alkyl chain lengths adopt a homogeneous hexagonal columnar structure, those with intermediate ones form mesophases with mixed structures. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2960,2974, 2008 [source] Alkyl side chain driven tunable red,yellow,green emission: Investigation on the new ,-conjugated polymers comprising of 2,7-carbazole unit and 2,1,3-benzo-thiadiazole units with different side chainsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 4 2008Junping Du Abstract Four new soluble polymers containing a 2,7-carbazole unit and a 2,1,3-benzothiadiazole unit in the main chain were synthesized by Suzuki polycondensation. Variation of the substituent groups (R) at 5-position of 2,1,3-benzothiadiazole unit resulted in different color emission of the copolymers. Thus, when R was CH3 (or H), the polymer showed yellow,green (or red) emission; whereas the polymers showed the emission from green to yellow,green, when R was CH2(CH2)5CH3 or CH2OCH(CH3)2. To investigate the nature of the color change, a Gaussian 03 program was used for estimation of the dihedral angles between a 5-R-2,1,3-benzothiadiazole unit and a 2,7-carbazole unit. The results showed that the different substituents at 5-position of 2,1,3-benzothiadiazole brought about different the dihedral angles, which gave the different conjugation levels to the polymers. Hence, the tunablity of emission color may be attributed to the different conjugation levels between 2,7-carbazole units and 5-R-2,1,3-benzothiadiazole units induced by simply changing substituent groups at 5-position of benzothiadiazole unit. Electrochemically, the copolymers exhibited a higher oxidation potential as well as the reversible reduction behavior bearing from 2,1,3-benzothiadiazole unit. To investigate the electroluminescent properties of the polymers, the nonoptimized devices were fabricated and the results showed that the electroluminescent emission wavelength was basically similar to that of the photoluminescent. All polymers showed good thermal stability with 5 wt % loss temperature of more than 296 °C. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1376,1387, 2008 [source] Synthesis and characterization of poly(phenylacetylene)s carrying oligo(ethylene oxide) pendantsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 3 2006Junwu Chen Abstract A group of new amphiphilic poly(phenylacetylene)s bearing polar oligo(ethylene oxide) pendants, poly{4-[2-(2-hydroxyethoxy)ethoxy]phenylacetylene} (1), poly(4-{2-[2-(2-hydroxyethoxy)-ethoxy]ethoxy}phenylacetylene) (2p), poly(3-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}phenylacetylene) (2m), poly(4-{2-[2-(2-methanesulfonyloxyethoxy)ethoxy]ethoxy}phenylacetylene) (3), poly(4-{2-[2-(p -toluenesulfonyloxyethoxy)ethoxy]ethoxy}phenylacetylene) (4), poly(4-{2-[2-(2-trimethylsilyloxy-ethoxy)ethoxy] ethoxy}phenylacetylene) (5), and poly(4-{2-[2-(2-chloroethoxy)ethoxy]ethoxy}phenylacetylene) (6), were synthesized with organorhodium complexes as the polymerization catalysts. The structures and properties of the polymers were characterized with IR, UV, NMR, and thermogravimetric analysis. 1, 2p, and 2m, the three polymers containing pendants with hydroxyl groups, were oligomeric or insoluble. The organorhodium complexes worked well for the polymerization of the monomers without hydroxyl groups, giving soluble polymers 3,6 with a weight-average molecular weight up to ,160 × 103 and a yield up to 99%. Z -rich polymers 3,6 could be prepared by judicious selections of the catalyst under optimal conditions. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1153,1167, 2006 [source] Facile synthesis, characterization, and potential applications of two kinds of polymeric pH indicators: Phenolphthalein formaldehyde and o -cresolphthalein formaldehydeJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2005Zhihong Liu Abstract Two kinds of applicable polymeric pH indicators were synthesized by the reaction of phenolphthalein and o -cresolphthalein with formaldehyde under alkaline conditions by a one-pot method. The synthesized products were fully characterized with Fourier transform infrared, 1H NMR, ultraviolet,visible spectroscopy, and gel permeation chromatography. The results indicated that the reaction was a typical phenol formaldehyde reaction. The dosage of formaldehyde and the reaction time were well controlled to obtain soluble polymers, instead of crosslinked products. The polymeric-pH-indicator-immobilized poly(vinyl alcohol) (PVA) membranes were easily fabricated and had good long-term stability under highly basic conditions and a fast equilibrium response. Moreover, the phenolphthalein formaldehyde immobilized PVA membrane had a linear response from pH 10.0 to 14.0, and so it has promise as a optical transducer for high pH value determinations. The o -cresolphthalein formaldehyde immobilized PVA membrane had a nonlinear response from pH 9.0 to 13.0. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1019,1027, 2005 [source] Effect of endo -xylanase-containing enzyme preparations and laccase on the solubility of rye bran arabinoxylanJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2003Roger Andersson Abstract Three commercial enzyme preparations with endo -xylanase activity, namely Bio-Feed Wheat, Bio-Feed Plus and Grindamyl H 640, and laccase have been tested for their effects on the solubilisation of arabinoxylan (AX) in rye bran or autoclaved rye bran. Autoclaving efficiently increased the availability of AX for enzymatic degradation. Both Bio-Feed Wheat (a monocomponent enzyme) and Bio-Feed Plus (a multicomponent preparation with different enzymatic activities) efficiently degraded the autoclaved rye bran AX into lower-molecular-weight fragments. As much as 70% of the xylose residues and 58% of the arabinose residues in the autoclaved bran were soluble after treatment with Bio-Feed Plus; the weight,average molecular weight of the detectable portion of these soluble polymers was 104,000,Da. Grindamyl H 640 solubilised only a small fraction of the AX in autoclaved rye bran; the molecular weight of these soluble fragments was higher than that of those released by the Bio-Feed xylanases. Addition of laccase during treatment with Bio-Feed Wheat or Grindamyl H 640 decreased the yield of water-soluble AX. © 2003 Society of Chemical Industry [source] Electrochemical behaviour and electrochemical polymerization of fluoro-substituted anilinesPOLYMER INTERNATIONAL, Issue 8 2002Atilla Cihaner Abstract The electrochemical behaviour of three fluoro-substituted aniline monomers, 2-fluoroaniline (2FAN), 3-fluoroaniline (3FAN) and 4-fluoroaniline (4FAN), was investigated in aqueous acidic and organic media by means of cyclic voltammetry (CV) studies. Constant potential electrolysis (CPE) of the monomers in acetonitrile,water mixture (1:1 by volume) using NaClO4 as supporting electrolyte yielded soluble polymers. The mechanism of electrochemical polymerization was investigated using in situ electron spin resonance (ESR) and in situ UV,VIS spectroscopic techniques for one of the monomers (4FAN). Both CV and in situ UV,VIS measurements indicated that the polymers obtained are in the emeraldine base form. In situ ESR studies indicated that electrochemical polymerization involves a radical-cation as an intermediate. Characterization of polymer products have been carried out using FTIR and NMR spectroscopic techniques, and thermal behaviour was studied using differential scanning calorimetry (DSC). It was found that conductivity can be imparted to as-synthesized polyfluoroanilines via iodine doping. © 2002 Society of Chemical Industry [source] Copolyesters of hydroxyphenylalkanoic acids: synthesis and thermal properties of poly{(4-oxybenzoate)- co -[8-(3-oxyphenyl)octanoate]} and poly{(3-bromo-4-oxybenzoate)- co -[8-(3-oxyphenyl)octanoate]}POLYMER INTERNATIONAL, Issue 6 2002Shiney Abraham Abstract Copolyesters of 8-(3-hydroxyphenyl)octanoic acid (HPOA), a monomer with kink and flexible segment derived from cardanol, and 4-hydroxybenzoic acid (HBA) or its brominated derivative, 3-bromo-4-hydroxybenzoic acid (BrHBA), were synthesized by acidolysis melt polycondensation of the in situ generated acetoxyderivative in the presence of magnesium acetate as catalyst by a one-pot method and characterized. The formation of the copolyester was confirmed by elemental analysis, FTIR and 1H NMR spectroscopy. These polymers were highly insoluble in most solvents except highly polar solvents, such as trifluoroacetic acid. The inherent viscosities of the soluble polymers were in the range of 0.8,1.1,dlg,1. The thermal and phase behaviour of the copolyesters were studied by DSC and polarized light microscopy. Poly{(4-oxybenzoate)- co -[8-(3-oxyphenyl)octanoate]} with 50 mole% of HPOA showed a birefringent melt with opalescence and a worm-like texture of a nematic phase. The effect of bromine substitution in the analogue poly{(3-bromo-4-oxybenzoate)- co -[8-(3-oxyphenyl)octanoate]} was evident when it showed a lower transition with minimum 45% Br-HBA at 225,°C showing enhanced melt processability. These copolymers, with hydrolytically degradable aliphatic carbonyl group and better crystallinity compared to poly(hydroxyalkanoate)s, are interesting in possible biomedical applications. © 2002 Society of Chemical Industry [source] | |||||||||||||