Home About us Contact
|
Home About us Contact | ||
|
|
||
Novel Poly (novel + poly)
Selected AbstractsNovel Poly(vinyl alcohol)-tetraethoxysilane hybrid matrix membranes as oxygen barriers,JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Mallikarjunagouda B. Patil Abstract Novel type of membranes based on poly(vinyl alcohol) crosslinked with tetraethoxysilane have been prepared by solution casting and solvent-evaporation method. The membranes thus formed were characterized by Fourier transform infrared spectroscopy (FTIR) to study the chemical interactions, X-ray diffraction (XRD), and thermogravimetry (TGA) to investigate morphological and thermal properties. Membranes were prepared in two different thicknesses (30 and 55 ,m) and used for measuring the oxygen permeability under varying feed pressures (maintaining the desired pressure differential across the membrane) in the range from 1 to 50 kg/cm2 pressure. Oxygen permeability of the membranes ranged from 0.0091 to 1.6165 Barrer for 30 ,m and 0.0305 to 0.1409 Barrer for 55-,m thick membranes by increasing the feed pressures on the feed side. Except at 50 kg/cm2 pressure, the observed oxygen permeability values are almost close to total permeability. Membranes of this study could be useful as oxygen barriers for applications in food packaging industries. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 273,278, 2007 [source] Water-Soluble Polyfluorenes as an Interfacial Layer Leading to Cathode-Independent High Performance of Organic Solar CellsADVANCED FUNCTIONAL MATERIALS, Issue 12 2010Seung-Hwan Oh Abstract Novel poly[(9,9-bis((6,-(N,N,N -trimethylammonium)hexyl)-2,7-fluorene)- alt -(9,9-bis(2-(2-(2-methoxyethoxy)ethoxy)ethyl)-9-fluorene)) dibromide (WPF-6-oxy-F) and poly[(9,9-bis((6,-(N,N,N -trimethylammonium)hexyl)-2,7-fluorene)- alt -(9,9-bis(2-(2-methoxyethoxy)ethyl)-fluorene)] dibromide (WPF-oxy-F) compounds are developed and the use of these water-soluble polymers as an interfacial layer for low-cost poly(3-hexylthiophene):phenyl-C61 butyric acid methyl ester (P3HT:PCBM) organic solar cells (OSCs) is investigated. When WPF-oxy-F or WPF-6-oxy-F is simply inserted between the active layer and the cathode as an interfacial dipole layer by spin-coating water-soluble polyfluorenes, the open-circuit voltage (Voc), fill factor (FF), and power-conversion efficiency (PCE) of photovoltaic cells with high work-function metal cathodes, such as Al, Ag, Au, and Cu, dramatically increases. For example, when WPF-6-oxy-F is used with Al, Ag, Au, or Cu, regardless of the work-function of the metal cathode, the Voc is 0.64, 0.64, 0.58, and 0.63,V, respectively, approaching the original value of the P3HT:PCBM system because of the formation of large interfacial dipoles through a reduction of the metal work-function. In particular, introducing WPF-6-oxy-F into a low-cost Cu cathode dramatically enhanced the device efficiency from 0.8% to 3.36%. [source] Electrochemical synthesis of PEDOT derivatives bearing imidazolium-ionic liquid moietiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 12 2009Markus Döbbelin Abstract Novel poly(3,4-ethylenedioxythiophene) (PEDOT) polymers bearing imidazolium-ionic liquid moieties were synthesized by electrochemical polymerizations. For this purpose, new functional monomers were synthesized having an 3,4-ethylenedioxythiophene (EDOT) unit and an imidazolium-ionic liquid with different anions such as tetrafluoroborate (BF), bis(trifluoromethane)sulfonimide ((CF3SO2)2N,), and hexafluorophosphate (PF). Next, polymer films were obtained by electrochemical synthesis in dicholoromethane solutions. Obtained polymers were characterized, revealing the characteristics of PEDOT in terms of electrochemical and spectroelectrochemical properties, FTIR, 1H NMR, and AFM microscopy. Interestingly, the hydrophobic character of electropolymerized films could be modified depending on the anion type. The hydrophobicity followed the trend PF > (CF3SO2)2N, > BF > pure PEDOT as determined by water contact angle measurements. Furthermore, the polymers could be dissolved in a range of polar organic solvents such as dimethylformamide, propylene carbonate, and dimethyl sulfoxide making these polymers interesting candidates for wet processing methods. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3010,3021, 2009 [source] Novel saturated red-emitting poly(p -phenylenevinylene) copolymers with narrow-band-gap units of 2,1,3-benzothiadiazole synthesized by a palladium-catalyzed Stille coupling reactionJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 11 2005Xianzhen Li Abstract Novel poly(p -phenylenevinylene) (PPV) copolymers derived from 1-methoxy-4-octyloxyphenylene (MOP), 2,1,3-benzothiadiazole (BT), and trans -1,2-bis(tributylstannyl)ethylene were first prepared by a palladium-catalyzed Stille coupling reaction. The feed ratios of MOP to BT were 99.5:0.5, 99:1, 95:5, 85:15, 70:30, and 50:50. An efficient energy transfer from the 2-methoxy-5-octyloxy- p -phenylenevinylene segment to the narrow-band-gap units was observed. The poly(2-methoxy-5-octyloxy- p -phenylenevinylene-2,1,3-benzothiadiazolevinylene) copolymers emitted deep red light. The maximum electroluminescence emission of these PPV copolymers occurred at 659,724 nm and was accompanied by gradual redshifting with an increasing BT concentration. The photophysical properties were examined in comparison with those of copolymers based on BT and fluorene or N -alkylcarbazole doped with the same BT concentration in the copolymer main chain. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2325-2336, 2005 [source] Novel Polymer Electrolyte Membrane, Based on Pyridine Containing Poly(ether sulfone), for Application in High-Temperature Fuel CellsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 21 2005Elefterios K. Pefkianakis Abstract Summary: Novel poly(aryl ether sulfone) copolymers containing 2,5-biphenylpyridine and tetramethyl biphenyl moieties were synthesized by polycondensation of 4-fluorophenyl sulfone with 2,5-(4,,4, dihydroxy biphenyl)pyridine and tetramethyl biphenyl diol. Copolymers with different molecular weights and different monomer compositions were obtained. These copolymers exhibit excellent film-forming properties, mechanical integrity, and high modulus up to 250,°C, high glass transition temperatures (above 280,°C) as well as high thermal stability up to 400,°C. In addition to the above properties required for PEMFC application, this novel material shows high oxidative stability and acid doping ability, enabling proton conductivity in the range of 10,2 S,·,cm,1 above 130,°C. Synthesis of copolymers with high acid uptake and ionic conductivity. [source] Preparation and characterization of novel poly[cyclotriphosphazene- co -(4,4,-sulfonyldiphenol)] nanofiber matricesPOLYMER INTERNATIONAL, Issue 12 2006Zhu Lu Abstract Novel poly[cyclotriphosphazene- co -(4,4,-sulfonyldiphenol)] nanofiber matrices were synthesized via a facile one-pot polymerization. The fibers are 20,50 nm in diameter and 500 nm or more in length. Uniform nanoscale fibers linked covalently with each other and formed three-dimensional matrices. The highly cross-linked chemical structure of the nanofiber matrices was measured by means of Fourier transform infrared and quantitative solid-state NMR spectroscopy. Experiments show the pH had an effect on the hydrolytic degradation of the polymer. The hydrolysis of the matrices could be accelerated by alkaline conditions. The as-synthesized nanofiber matrices have potential applications in tissue engineering materials. Copyright © 2006 Society of Chemical Industry [source] Synthesis and characterization of thermotropic liquid crystalline poly(aryl ether ketone) copolymers with pendant 3-(trifluoromethyl) phenyl groupsPOLYMER INTERNATIONAL, Issue 6 2006Guibin Wang Abstract Novel poly(aryl ether ketone) copolymers with pendant 3-(trifluoromethyl)phenyl groups were synthesized by the reaction of a crystal-disrupting monomer, 3-(trifluoromethyl)phenylhydroquinone (FH) and a mesogenic monomer, 4,4,-biphenol (BP) with 1,4-bis(p -fluorobenzoyl)benzene (BF). Thermotropic liquid crystalline behavior of the copolymers was investigated by means of differential scanning calorimetry, polarized optical microscope and wide-angle X-ray diffraction. As a result, the copolymers with the respective molar ratios of FH/BP/BF of 0/100/100,10/90/100 and 80/20/100,100/0/100 were semi-crystalline without liquid crystalline properties, and amorphous polymers, respectively. In contrast, copolymers with the molar ratio of FH/BP/BF of 20/80/100,70/30/100 had liquid crystalline characteristics. Interestingly, the formation of a highly ordered smectic phase was confirmed for copolymers with the molar ratio of FH/BP/BF of 20/80/100,50/50/100, respectively. All the liquid crystalline copolymers had a wide liquid crystalline temperature range (57,75 °C). Copyright © 2006 Society of Chemical Industry [source] Synthesis of poly(aryl ether ketone)s containing diphenyl moieties by electrophilic Friedel,Crafts solution polycondensationPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 12 2009Mingzhong Cai Abstract A new monomer, 4,4,-bis(4-phenoxybenzoyl)diphenyl (BPOBDP), was prepared by Friedel,Crafts reaction of 4-bromobenzoyl chloride and diphenyl, followed by condensation with potassium phenoxide. Novel poly(ether ketone ketone) (PEKK)/poly(ether ketone diphenyl ketone ether ketone ketone) (PEKDKEKK) copolymers were synthesized by electrophilic Friedel,Crafts solution copolycondensation of isophthaloyl chloride (IPC) with a mixture of diphenyl ether (DPE) and BPOBDP, in the presence of anhydrous aluminum chloride and N -methyl-pyrrolidone (NMP) in 1,2-dichloroethane (DCE). The copolymers obtained were characterized by various analytical techniques such as FT-IR, DSC, TGA, and wide-angle X-ray diffraction (WAXD). The results showed that the resulting copolymers exhibited excellent thermal stability due to the existence of diphenyl moieties in the main chain. The glass transition temperatures are above 152°C, the melting temperatures are above 276°C, and the temperatures at a 5% weight loss are above 548°C in nitrogen. The copolymers with 50,70,mol% BPOBDP had tensile strengths of 101.5,102.7,MPa, Young's moduli of 3.23,3.41,GPa, and elongations at break of 12,17%. All these copolymers were semicrystalline and insoluble in organic solvents. Copyright © 2008 John Wiley & Sons, Ltd. [source] Novel interpenetrating networks with shape-memory propertiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2007Shifeng Zhang Abstract Novel polyesterurethane/poly(ethylene glycol) dimethacrylate (PEGDMA) interpenetrating networks (IPNs) with good shape-memory properties were synthesized using solvent casting method. The star-shaped oligo[(rac -lactide)- co -glycolide] was coupled with isophorone diisocyanate to form a polyesterurethane network (PULG), and PEGDMA was photopolymerized to form another polyetheracrylate network. IPNs were transparent and gel content exceeded 92%. The values of strain fixity rate and strain recovery rate were above 93%. PULG and PEGDMA networks in IPNs were amorphous and did not show any characteristic diffraction peaks in X-ray diffraction spectra. Only one glass transition temperature (Tg) of the IPNs between Tg of PEGDMA and PULG was observed, which was proportional to PEGDMA content. PULG and PEGDMA networks were miscible when PEGDMA content was below 50 wt %. The hydrophilicity, transition temperatures, and mechanical properties of IPNs could be conveniently adjusted through variation of network compositions to match the promising potential clinical or medical applications. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 768,775, 2007 [source] Aqueous Lithium-ion Battery LiTi2(PO4)3/LiMn2O4 with High Power and Energy Densities as well as Superior Cycling Stability**,ADVANCED FUNCTIONAL MATERIALS, Issue 18 2007J.-Y. Luo Abstract Porous, highly crystalline Nasicon-type phase LiTi2(PO4)3 has been prepared by a novel poly(vinyl alcohol)-assisted sol,gel route and coated by a uniform and continuous nanometers-thick carbon thin film using chemical vapor deposition technology. The as-prepared LiTi2(PO4)3 exhibits excellent electrochemical performance both in organic and aqueous electrolytes, and especially shows good cycling stability in aqueous electrolytes. An aqueous lithium-ion battery consisting of a combination of LiMn2O4 cathode, LiTi2(PO4)3 anode, and a 1 M Li2SO4 electrolyte has been constructed. The cell delivers a capacity of 40 mA,h,g,1 and a specific energy of 60 W,h,kg,1 with an output voltage of 1.5 V based on the total weight of the active electrode materials. It also exhibits an excellent cycling stability with a capacity retention of 82,% over 200 charge/discharge cycles, which is much better than any aqueous lithium-ion battery reported. [source] Synthesis of Inorganic,Organic Diblock Copolymers as a Precursor of Ordered Mesoporous SiCN Ceramic,ADVANCED MATERIALS, Issue 17 2007D. Nghiem A novel poly(vinyl)silazane- block -polystyrene diblock copolymer is successfully synthesized by living free-radical polymerization via a reversible addition fragmentation chain transfer (RAFT) route (see figure). The obtained diblock copolymer, having an inorganic volume fraction of 0.69, leads to phase-separation at the nanoscale to form an ordered nanostructure, which is converted to well-ordered mesoporous SiCN ceramic after heating at 800,°C and maintained up to 1400,°C. [source] Influence of azobenzene units on imidization kinetic of novel poly(ester amic acid)s and polymers properties before and after cyclodehydrationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Ewa Schab-Balcerzak Abstract In this article, the imidization reaction kinetic of novel poly(ester amic acid)s with azobenzene units as side groups was studied by dynamic experiments by means of differential scanning calorimetry. Polymers differ in the number of chromophore moieties in their repeating unit and position in which azobenzene group is attached to the polymer chain. The kinetic parameters of poly(ester amic acid)s conversion to poly(ester imide)s was compared with data calculated for parent polymer, that is, without azobenzene groups. For the first time to our knowledge, the imidization kinetic of polymers with side azobenzene groups was studied. Kinetic parameters, such as the activation energy and frequency factor were estimated with the by Ozawa model [(E(O) and A(O)), respectively] and Kissinger model [(E(K) and A(K), respectively]. The values of activation energy determined with both models were in the range 167.1,198.3 kJ/mol. The lowest activation energy of imidization reaction exhibited polymer in which azobenzene units were placed between amide linkages. Polymers were characterized by FTIR, 1H-NMR, X-ray, and UV,vis methods. The glass transition temperature of resultant poly(ester imide)s was in the range of 217,237°C. The presence of chromophore units slightly decreased Tg and significantly improved their solubility and optical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Synthesis and characterization of novel poly(arylenevinylene) derivativeJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2008Song Se-Yong Abstract The new poly(arylenevinylene) derivative composed naphthalene phenylene vinylene backbone was developed. The theoretical calculation showed that the model compound of the obtained polymer was highly distorted between the stryl and naphthalene units as well as between the backbone and fluorene side units. The polymer was synthesized by the palladium catalyzed Suzuki coupling reaction with 2,6-(1,,2,-ethylborate)-1,5-dihexyloxynaphtalene and 1,2-bis(4,-bromophenyl)-1-(9,,9,-dihexyl-3-fluorenyl)ethene. The structure of the polymer was confirmed by 1H NMR, IR, and elemental analysis. The weight,average molecular weight of the polymer is 29,800 with the polydispersity index of 1.87. The new polymer showed good thermal stability with high Tg of 195°C. The bright blue fluorescence (,max = 475 nm) was observed both in solution and film of new polymer with naphthalene phenylene vinylene backbone. Double layer LED devices with the configuration of ITO/PEDOT/polymer/LiF/Ca/Al showed a turn-on voltage at around 4.5 V, the maximum luminance of 150 cd/m2, and the maximum efficiency of 0.1 cd/A. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Synthesis and characterization of novel poly(o -toluidine) montmorillonite nanocomposites: Effect of surfactant on intercalationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007Rahul Singhal Abstract The investigation of clay based polymer nanocomposites has opened the door for the development of novel, ecofriendly advanced nano materials that can be safely recycled. Because of their nanometer size dispersion, these nanocomposites often have superior physical and mechanical properties. In this study, novel nanocomposites of poly(o -toluidine) (POT) and organically modified montmorillonite (MMT) were synthesized using camphor sulfonic acid (CSA), cetyl pyridinum chloride (CPCl), and N -cetyl- N,N,N -trimethyl ammonium bromide (CTAB) to study the role of surfactant modification on the intercalation. The in situ intercalative polymerization of POT within the organically modified MMT layers was analyzed by FTIR, UV,visible, XRD, SEM as well as TEM studies. The average particle size of the nanocomposites was found to be in the range 80,100 nm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 [source] Synthesis and characterization of novel poly(arylene ether)s based on 9,10-bis-(4-fluoro-3-trifluoromethylphenyl) anthracene and 2,7-bis-(4-fluoro-3-trifluoromethylphenyl) fluoreneJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Arun K. Salunke Abstract Two new bisfluoro monomers 9,10-bis-(4-fluoro-3-trifluoromethylphenyl) anthracene and 2,7-bis-(4-fluoro-3-trifluoromethylphenyl) fluorene have been synthesized by the cross-coupling reaction of 2-fluoro-3-trifluoromethyl phenyl boronic acid with 9,10-dibromo anthracene and 2,7-dibromo fluorine, respectively. These two bisfluoro compounds were used to prepare several poly(arylene ether)s by aromatic nucleophilic displacement of fluorine with various bisphenols; such as bisphenol-A, bisphenol-6F, bishydroxy biphenyl, and 9,9-bis-(4-hydroxyphenyl)-fluorene. The products obtained by displacement of the fluorine atoms exhibits weight-average molar masses up to 1.5 ×105 g mol,1 and number average molecular weight up to 6.8 × 104 g mol,1 in GPC. These poly(arylene ether)s show very high thermal stability even up to 490°C for 5% weight loss occurring at this temperature in TGA in synthetic air and showed glass transition temperature observed up to 310°C. All the polymers are soluble in a wide range of organic solvents, e.g., CHCl3, THF, NMP, and DMF. Films cast from DMF solution are brittle in nature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 [source] Design, synthesis, characterization and in-vivo activity of a novel salmon calcitonin conjugate containing a novel PEG-lipid moietyJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2010Weiqiang Cheng Abstract Objectives The aim of the study was to explore (1) the synthesis of a novel poly(ethylene glycol) modified lipid (PEG-lipid, PL) containing a chemically active tri-block linker, ,-maleimido lysine (Mal), and its conjugation with salmon calcitonin (sCT), and (2) the biophysical properties and activity of the resulting conjugate, Mal-PL-sCT, relative to the control, 2PEG-Mal-sCT, which comprises sCT conjugated with ,-palmitoyl- N -,-maleimido- l -lysine at cysteine 1 and cysteine 7, and PEG moieties at lysine 11 and lysine 18 via a conventional stepwise method. Methods The PEG-lipid was obtained by condensing palmitic acid derivative of ,-maleimido lysine with methoxy poly(ethylene glycol) amine. Under reductive conditions, the PEG-lipid readily reacted with sCT to yield the resultant compound, Mal-PL-sCT. Key findings Dynamic light scattering analyses suggested that Mal-PL-sCT and 2PEG-Mal-sCT exhibited robust helical structures with a high tendency to aggregate in water. Both compounds were more stable against intestinal degradation than sCT, although Mal-PL-sCT was less stable than 2PEG-Mal-sCT. However, 2PEG-Mal-sCT did not possess hypocalcaemic activity while Mal-PL-sCT retained the hypocalcaemic activity of sCT when it was subcutaneously injected in the rat model. Multiple functional groups may be conjugated to a peptide via a tri-block linker without the risk of obliterating the intrinsic bioactivity of the peptide. Conclusions The resultant novel PEG-lipid has a potential role to optimize protein and peptide delivery. [source] Solution, thermal and optical properties of novel poly(pyridinium salt)s derived from conjugated pyridine diamines,JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2010Alexi K. Nedeltchev Abstract Several novel poly(pyridinium salt)s with heterocyclic pyridine moieties in their backbones with tosylate and triflimide counterions were prepared by either ring-transmutation polymerization reaction of phenylated-bis(pyrylium tosylate) with isomeric pyridine diamines of 4-phenyl-2,6-bis(4-aminophenyl)pyridine in dimethyl sulfoxide (DMSO) for 48 h at 130,140 °C or by metathesis reaction of the respective tosylate polymers with lithium triflimide in DMSO at about 60 °C. Their chemical structures were characterized by FTIR, 1H, 13C NMR spectroscopy, and elemental analysis. Their number-average molecular weights (Mn) were in the range of 8,000,51,000 and their polydispersities in the range of 1.18,2.13 as determined by gel permeation chromatography. They had excellent thermal stabilities of 340,458 °C and high glass transition temperatures >200 °C. As they showed good solubilities in common organic solvents, their solution properties were also characterized for their lyotropic liquid-crystalline properties with polarizing optical microscopy (POM) studies. Their photoluminescent properties were examined by using a spectrofluorometer in both solution and solid states. Their quantum yields were rather low, which were in the range of 1.3,2.0%. Additionally, hand-drawn fibers from the melts were examined to determine their morphologies with a number of microscopic techniques including POM, scanning electron microscopy, and transmission electron microscopy. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 [source] Synthesis and characterization of novel poly(p -phenylenevinylene) derivatives containing phenothiazine-5-oxide and phenothiazine-5, 5-dioxide moietiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 18 2007L. Y. Yang Abstract PPV-based copolymers containing phenothiazine-5-oxide and phenothiazine-5, 5-dioxide moieties have been successfully synthesized by Wittig-Horner reaction and characterized by means of UV-vis, photoluminescence, electroluminescence spectra, and cyclic voltammetry. All of these copolymers can be dissolved in common organic solvents such as chloroform, tetrahydrofuran, and toluene. The PL maxima in the film state are located at 582, 556, and 552 nm for P1, P2, and P3, respectively. The HOMO and LUMO levels of P2 are found to be ,5.21 and ,2.68 eV, respectively; whereas those of P3 are found to be ,5.26 and ,2.71 eV, respectively. The cyclic voltammetry result indicates that the conversion of electron-donating sulfide to electron-withdrawing sulfoxide or sulfone group in polymers plays a dominating role in increasing its oxidation potential. Yellowish-green light ranging from 568 to 540 nm was observed for the single layer device with the configuration of ITO/Polymer/Ca/Al. Double layer devices with Zn (BTZ)2as a hole blocking layer exhibited enhanced EL performance compared to the single layer devices. The maximum brightness of the double layer devices of P1, P2, and P3 is 278, 400, and 796 cd/m2, respectively. The results of EL and electrochemical analyses revealed that they are promising candidate materials for organic, light-emitting diodes with hole-transporting ability. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4291,4299, 2007 [source] Preparation of novel poly(ethylene oxide- co -glycidol)-graft-poly(,-caprolactone) copolymers and inclusion complexation of the grafted chains with ,-cyclodextrinJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 11 2006Juan Huang Abstract A well-defined comblike copolymer of poly(ethylene oxide- co -glycidol) [(poly(EO- co -Gly)] as the main chain and poly(,-caprolactone) (PCL) as the side chain was successfully prepared by the combination of anionic polymerization and ring-opening polymerization. The glycidol was protected by ethyl vinyl ether to form 2,3-epoxypropyl-1-ethoxyethyl ether (EPEE) first, and then ethylene oxide was copolymerized with EPEE by an anionic mechanism. The EPEE segments of the copolymer were deprotected by formic acid, and the glycidol segments of the copolymers were recovered after saponification. Poly(EO- co -Gly) with multihydroxyls was used further to initiate the ring-opening polymerization of ,-caprolactone in the presence of stannous octoate. When the grafted copolymer was mixed with ,-cyclodextrin, crystalline inclusion complexes (ICs) were formed, and the intermediate and final products, poly(ethylene oxide- co -glycidol)- graft -poly(,-caprolactone) and ICs, were characterized with gel permeation chromatography, NMR, differential scanning calorimetry, X-ray diffraction, and thermogravimetric analysis in detail. The obtained ICs had a channel-type crystalline structure, and the ratio of ,-caprolactone units to ,-cyclodextrin for the ICs was higher than 1:1. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3684,3691, 2006 [source] Synthesis, characterization, and antimicrobial activity of some novel poly(ether ketone)sJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2003Samir A. Patel Abstract Low molecular weight poly(ether ketone)s were synthesized from phenol, 1,4-phenylenedioxy diacetylchloride, chloroacetylchloride, and dichloroalkanes [1,2-dichloroethane and dichloromethane] by a Friedel,Crafts reaction with anhydrous aluminum chloride as a catalyst and carbon disulfide as a solvent. The conditions for the preparation of the poly(ether ketone)s and the chlorine contents obtained with the Carius method were examined, and a reaction scheme for each resin was established. The molecular weights and polydispersities of the resins were obtained by gel permeation chromatography. The polyketones were characterized by IR spectroscopy. The characteristic frequencies due to different functional groups were assigned. The thermal properties of the resins were studied with thermogravimetry and differential scanning calorimetry. The characteristic temperatures of thermal degradation for the poly(ether ketone)s were evaluated with thermogravimetric analysis. The kinetic parameters for the decomposition reactions of the resins were obtained with Broido and Doyle's method, and the heats of fusion were obtained from differential scanning calorimetry thermograms. The polyketones were thermally stable up to 200 °C. All the polyketones were tested for their microbial properties against bacteria, fungi, and yeast. The effect of poly(ether ketone)s on the growth of these microorganisms was investigated, and the polyketones were found to inhibit the growth of the microorganisms to a considerable extent. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2335,2344, 2003 [source] Preparation of high-temperature polyurethane by alloying with reactive polyamideJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2002Tsutomu Takeichi Abstract A series of novel poly(urethane amide) films were prepared by the reaction of a polyurethane (PU) prepolymer and a soluble polyamide (PA) containing aliphatic hydroxyl groups in the backbone. The PU prepolymer was prepared by the reaction of polyester polyol and 2,4-tolylenediisocyanate and then was end-capped with phenol. Soluble PA was prepared by the reaction of 1-(m -aminophenyl)-2-(p -aminophenyl)ethanol and terephthaloyl chloride. The PU prepolymer and PA were blended, and the clear, transparent solutions were cast on glass substrates; this was followed by thermal treatments at various temperatures to produce reactions between the isocyanate group of the PU prepolymer and the hydroxyl group of PA. The opaque poly(urethane amide) films showed various properties, from those of plastics to those of elastomers, depending on the ratio of the PU and PA components. Dynamic mechanical analysis showed two glass-transition temperatures (Tg's), a lower Tg due to the PU component and a higher Tg due to the PA component, suggesting that the two polymer components were phase-separated. The rubbery plateau region of the storage modulus for the elastic films was maintained up to about 250 °C, which is considerably higher than for conventional PUs. Tensile measurements of the elastic films of 90/10 PU/PA showed that the elongation was as high as 347%. This indicated that the alloying of PU with PA containing aliphatic hydroxyl groups in the backbone improved the high-temperature properties of PU and, therefore, enhanced the use temperature of PU. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3497,3503, 2002 [source] Monolithic poly(1,2-bis(p -vinylphenyl)ethane) capillary columns for simultaneous separation of low- and high-molecular-weight compoundsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 15-16 2009Andreas Greiderer Abstract Monolithic poly(1,2-bis(p -vinylphenyl)ethane (BVPE)) capillary columns were prepared by thermally initiated free radical polymerisation of 1,2-bis(p -vinylphenyl)ethane in the presence of inert diluents (porogens) and ,,,,-azoisobutyronitrile (AIBN) as initiator. Polymerisations were accomplished in 200 ,m ID fused silica capillaries at 65°C and for 60 min. Mercury intrusion porosimetry measurements of the polymeric RP support showed a broad bimodal pore-size-distribution of mesopores and small macropores in the range of 5,400 nm and flow-channels in the ,m range. N2 -adsorption (BET) analysis resulted in a tremendous enhancement of surface area (101 m2/g) of BVPE stationary phases compared to typical organic monoliths (,20 m2/g), indicating the presence of a considerable amount of mesopores. Consequently, the adequate proportion of both meso- and (small) macropores allowed the rapid and high-resolution separation of low-molecular-weight compounds as well as biomolecules on the same monolithic support. At the same time, the high fraction of flow-channels provided enhanced column permeability. The chromatographic performance of poly(1,2-bis(p -vinylphenyl)ethane) capillary columns for the separation of biomolecules (proteins, oligonucleotides) and small molecules (alkyl benzenes, phenols, phenons) are demonstrated in this article. Additionally, pressure drop versus flow rate measurements of novel poly(1,2-bis(p -vinylphenyl)ethane) capillary columns confirmed high mechanical robustness, low swelling in organic solvents and high permeability. Due to the simplicity of monolith fabrication, comprehensive studies of the retention and separation behaviour of monolithic BVPE columns resulted in high run-to-run and batch-to-batch reproducibilities. All these attributes prove the excellent applicability of monolithic poly(1,2-bis(p -vinylphenyl)ethane) capillary columns for ,-HPLC towards a huge range of analytes of different chemistries and molecular sizes. [source] Synthesis and Characterization of N -Propargyl Cinnamamide Polymers and CopolymersMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 3 2007Jianping Deng Abstract This paper deals with synthesis and characterization of a novel poly(N -propargylamide) containing cinnamamide groups (poly(1)) in its side chains. Monomer 1, CHCCH2NHCOCHCH(C6H5), was synthesized and polymerized with a rhodium catalyst, (nbd)Rh+B,(C6H5)4 (nbd,=,2,5-norbornadiene). Effects of some factors on polymerization of monomer 1 such as solvent, temperature, and the ratio of monomer/catalyst were investigated in detail; polymers with moderate number-average molecular weights () and low index of polydispersity () were obtained. To improve the polymers' solubility and to elucidate whether poly(1) could form helical conformation, another N -propargylamide monomer 2, CHCCH2NHCOCH(CH2CH3)2, was employed to accomplish copolymerization with monomer 1. Copolymerization with monomer 2 improved obviously the solubility of the (co)polymers; the copolymers with certain monomer ratios could form helices under the examined conditions according to the related UV-vis spectra. [source] Blue Emission of a Soluble Poly(p -phenylene) with a Cross-Conjugated Bisimidazole-Based ChromophoreMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 1 2007Frank Dierschke Abstract A novel poly(p -phenylene) (6) has been synthesized by a cruciform combination of a polyphenylene backbone with 2,2,-(p -phenylene)-bis(4,5-diphenylimidazole) (5) as an additional, orthogonal chromophore. Polymer 6 showed in solution and in the solid state, a blue-green emission, which is obviously arising from the second bisimidazole-based chromophore. UV-Vis spectroscopy, and cyclic voltammetry revealed that the optical and electronic properties of 6 were fully determined by the incorporated 2,2,-(1,4-phenylene)bisimidazole structure. The bisimidazole unit led to high solubility and, despite the steric demand of the substituents, at the same time to the blue-green emission of the poly(p -phenylene) (6). In addition, the oxidation of 6 with potassium ferricyanide yielded a low bandgap polymer with a quinoid-type structure and a bandgap of 1.6 eV. [source] Atom Transfer Radical Polymerization of Glycidyl Methacrylate: A Functional MonomerMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 16 2004Pedro Francisco Cañamero Abstract Summary: A detailed investigation of the polymerization of glycidyl methacrylate (GMA), an epoxy-functional monomer, by atom transfer radical polymerization (ATRP) was performed. Homopolymers were prepared at relatively low temperatures using ethyl 2-bromoisobutyrate (EBrIB) as the initiator and copper halide (CuX) with N,N,N,,N,,N,-pentamethyldiethylenetriamine (PMDETA) as the catalyst system. The high polymerization rate in the bulk did not permit polymerization control. However, homopolymerization in solution enabled us to explore the effects of different experimental parameters, such as temperature, solvent (toluene vs. diphenyl ether) and initiator concentration, on the controllability of the ATRP process. SEC analysis of the homopolymers synthesized confirmed the importance of solvent character on molecular weight control, the lowest polydispersity indices () and the highest efficiencies being found when the polymerizations were performed in diphenyl ether in combination with a mixed halide technique. A novel poly(glycidyl methacrylate)- block -poly(butyl acrylate) (PGMA- b -PBA) diblock copolymer was prepared through ATRP using PGMA-Cl as a macro-initiator. This chain growth experiment demonstrated a good living character under the conditions employed, while simultaneously indicating a facile synthetic route for this type of functional block copolymer. In addition, the isotacticity parameter for the PGMAs obtained was estimated using 1H NMR analysis which gave a value of ,GMA,=,0.26 in agreement with that estimated in conventional radical polymerization. SEC chromatograms of PGMA-Cl macroinitiator and PGMA- b -PBA diblock copolymer. [source] Study on superabsorbent composite XXV.POLYMER COMPOSITES, Issue 4 2010Synthesis, characterization, swelling behaviors of poly(acrylic acid- co - N -acryloylmorpholine)/attapulgite superabsorbent composites In this work, a novel poly(acrylic acid- co - N -acryloylmorpholine)/attapulgite superabsorbent composite was prepared by graft copolymerization among acrylic acid, N -acryloylmorpholine and attapulgite in aqueous solution, using N,N, -methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator. The result from FTIR spectra showed that OH of attapulgite participated in graft copolymerization with acrylic acid and N -acryloylmorpholine. Proper monomer ratio and atapulgite content could form a loose surface, and improve reswelling ability and initial swelling rate. The buffer action of the COOH and COO, groups in the superabsorbent composite keeps the water absorbency a rough constant in the pH range of 4.4,9.6. Both polarity and structure of an organic solvent are responsible for the phase transition point of the superabsorbent composite. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers [source] Preparation and characterization of novel poly[cyclotriphosphazene- co -(4,4,-sulfonyldiphenol)] nanofiber matricesPOLYMER INTERNATIONAL, Issue 12 2006Zhu Lu Abstract Novel poly[cyclotriphosphazene- co -(4,4,-sulfonyldiphenol)] nanofiber matrices were synthesized via a facile one-pot polymerization. The fibers are 20,50 nm in diameter and 500 nm or more in length. Uniform nanoscale fibers linked covalently with each other and formed three-dimensional matrices. The highly cross-linked chemical structure of the nanofiber matrices was measured by means of Fourier transform infrared and quantitative solid-state NMR spectroscopy. Experiments show the pH had an effect on the hydrolytic degradation of the polymer. The hydrolysis of the matrices could be accelerated by alkaline conditions. The as-synthesized nanofiber matrices have potential applications in tissue engineering materials. Copyright © 2006 Society of Chemical Industry [source] Influence of the COOH and COONa groups and crosslink density of poly(acrylic acid)/montmorillonite superabsorbent composite on water absorbencyPOLYMER INTERNATIONAL, Issue 9 2001Jihuai Wu Abstract A novel poly(acrylic acid)/montmorillonite superabsorbent composite with a water absorbency of 1100 times its own weight was synthesized by the graft copolymerization of acrylic acid with a cross-linking agent in the presence of montmorillonite ultrafine powder. The influence of the amount of crosslinker and montmorillonite on water absorbency has been investigated. It was found that a crosslinker concentration of 0.03,wt% and 30,wt% montmorillonite gave the best results. The collaborative absorbent effect of sodium carboxylate and carboxylic acid groups was superior to that of sodium carboxylate or carboxylic acid groups alone, and the composite with a ratio of about 2/3 for sodium carboxylate to carboxyl acid groups possessed the highest water absorbence. © 2001 Society of Chemical Industry [source] Detection of allergen specific immunoglobulins by microarrays coupled to microfluidicsPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 8 2009Marina Cretich Dr. Abstract Allergen microarrays are under development for a component-resolved diagnosis of Type I (IgE-mediated) allergies. Here we report an improved microarray coupled to microfluidics for the detection of allergen specific immunoglobulin E (IgE). The signal intensity for IgE detection in serum has been improved by using glass slides coated with a novel poly[DMA- co -NAS] brush copolymer which is able to immobilize allergens in their native conformation and by carrying out the incubation step in dynamic conditions. The assay, fully automated, was performed in a microcell, using a software-controlled fluidic processor, to bring assay reagents on the surface of the array. Microfluidics turns the binding between serum immunoglobulins and immobilized allergens from a diffusion-limited to a kinetic-limited process by ensuring an efficient mixing of serum samples on the surface of the microarray. As a result of this, the binding of high affinity IgE antibodies is enhanced whereas that of low affinity IgG antibodies, which are present at higher concentration, is impaired paving the way to more accurate and sensitive results. [source] | ||||||||||||||||||||||||||||