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Resulting Polymers (resulting + polymer)
Selected AbstractsUsing hydroxypropyl-,-cyclodextrin for the preparation of hydrophobic poly(ketoethyl methacrylate) in aqueous mediumJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Lei Ding Abstract This work was committed to the polymerization of hydrophobic ketoethyl methacrylate monomer in aqueous medium in the presence of cyclodextrin, instead of polymerizing the monomer in toxic and volatile organic solvents. For this purpose, a new ketoethyl methacrylate monomer, p -methylphenacylmethacrylate (MPMA), was synthesized from the reaction of p -methylphenacylbromide with sodium methacrylate in the presence of triethylbenzylammonium chloride. The monomer was identified with FTIR, 1H and 13C-NMR spectroscopies. Hydroxypropyl-,-cyclodextrin (HPCD) was used to form a water-soluble host/guest inclusion complex (MPMA/HPCD) with the hydrophobic monomer. The complex was identified with FTIR and NMR techniques and polymerized in aqueous medium using potassium persulfate as initiator. During polymerization the resulting hydrophobic methacrylate polymer precipitated out with a majority of HPCD left in solution and a minority of HPCD bonded on the resulting polymer. The thus-prepared polymer exhibited little difference from the counterparts obtained in organic solvent in number average molecular weight (Mn), polydispersity (Mw/Mn) and yield. The investigation provides a novel strategy for preparing hydrophobic ketoethyl methacrylate polymer in aqueous medium by using a monomer/HPCD inclusion complex. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Synthesis and reactivity of allyl nickel(II) N -heterocyclic carbene enolate complexesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 16 2007Stefan Benson Abstract Two new N -heterocyclic carbene enolate nickel(II) allyl complexes have been prepared and their activity towards ethylene polymerization was investigated. It was found that in the presence of diethyl zinc, the carbene enolate complex bearing a nitro substituent produces highly linear polyethylene of modest molecular weight and high polydispersity. The influence of the reaction parameters on catalytic activity and the characteristics of the resulting polymer were investigated through systematic variation of the time, temperature, and diethyl zinc concentration. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45:3637,3647, 2007 [source] Titanium-mediated living radical styrene polymerizations.JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 6 2006Abstract The effects of solvents, additives, ligands, and solvent in situ drying agents as well as catalyst and initiator concentrations have been investigated in the Cp2TiCl-catalyzed radical polymerization of styrene initiated by epoxide radical ring opening. On the basis of the solubilization of Cp2Ti(III)Cl and the polydispersity of the resulting polymer, the solvents rank as follows: dioxane , tetrahydrofuran > diethylene glycol dimethyl ether > methoxybenzene > diphenyl ether , bulk > toluene , pyridine > dimethylformamide > 1-methyl-2-pyrrolidinone > dimethylacetamide > ethylene carbonate, acetonitrile, and trioxane. Alkoxide additives such as aluminum triisopropoxide and titanium(IV) isopropoxide are involved in alkoxide ligand exchange with the epoxide-derived titanium alkoxide and lead to broad molecular weight distributions, whereas similarly to strongly coordinating solvents, ligands such as bipyridyl block the titanium active site and prevent the polymerization. By contrast, softer ligands such as triphenylphosphine improve the polymerization in less polar solvents such as toluene. Although mixed hydrides such as lithium tri- tert -butoxyaluminum hydride, sodium borohydride, and lithium aluminum hydride react with bis(cyclopentadienyl)titanium dichloride to form mixed titanium hydride species ineffective in polymerization control, simple hydrides such as lithium hydride, sodium hydride, and especially calcium hydride are particularly effective as in situ trace water scavengers in this polymerization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2015,2026, 2006 [source] Synthesis of well-defined AB20 -type star polymers with cyclodextrin-core by combination of NMP and ATRPJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 18 2005Yutaka Miura Abstract The synthesis of an AB20 -type heteroarm star polymer consisting of a polystyrene arm and 20-arms of poly(methyl methacrylate) or poly(tert -butyl acrylate) was carried out using the combination of nitroxide-mediated polymerization (NMP) and atom transfer radical polymerization (ATRP). The NMP of styrene was carried out using mono-6-[4-(1,-(2,,2,,6,,6,-tetramethyl-1,-piperidinyloxy)-ethyl)benzamido]-,-cyclodextrin peracetate (1) to afford end-functionalized polystyrene with an acetylated ,-cyclodextrin (,-CyD) unit (prepolymer 2) with a number-average molecular weight (Mn) of 11700 and a polydispersity (Mw/Mn) of 1.17. After deacetylation of prepolymer 2, the resulting polymer was reacted with 2-bromoisobutyric anhydride to give end-functionalized polystyrene with 20(2-bromoisobutyrol)s ,-CyD, macroinitiator 4. The copper (I)-mediated ATRP of methyl methacrylate (MMA) and tert -butyl acrylate (tBA) was carried out using macroinitiator 4. The resulting polymers were isolated by SEC fractionation to produce AB20 -type star polymers with a ,-CyD-core, 5. The well-defined structure of 5 with weight-average molecular weight (Mw)s of 13,500,65,300 and Mw/Mn's of 1.26,1.28 was demonstrated by SEC and light scattering measurements. The arm polymers were separated from 5 by destruction with 28 wt % sodium methoxide in order to analyze the details of their characteristic structure. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4271,4279, 2005 [source] Synthesis of a novel block copolymer containing aromatic polyamide and fluoroethylene segmentsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 18 2003Arata Korematsu A novel block copolymer containing aromatic polyamide (aramid) and fluoroethylene segments was synthesized by a two-step, low-temperature solution polycondensation. In the first step, a telechelic diamine was prepared by the reaction of 3,4,-diaminodiphenylether and tetrafluorosuccinic acid in the presence of 1,3-dicyclohexylcarbodiimide as a condensing agent. Next, the block copolymer was synthesized by the polycondensation of the telechelic diamine and isophthaloyl chloride. The number-average molecular weight of this polymer, according to gel permeation chromatography, was over 1.7 × 104. Incorporating fluoroethylene segments improved the solubility of the resulting polymer with respect to conventional aramids. [source] Radical and cationic polymerizations of 3-ethyl-3-methacryloyloxymethyloxetaneJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 9 2001Tsuneyuki Sato Abstract 3-Ethyl-3-methacryloyloxymethyloxetane (EMO) was easily polymerized by dimethyl 2,2,-azobisisobutyrate (MAIB) as the radical initiator through the opening of the vinyl group. The initial polymerization rate (Rp) at 50 °C in benzene was given by Rp = k[MAIB]0.55 [EMO]1.2. The overall activation energy of the polymerization was estimated to be 87 kJ/mol. The number-average molecular weight (M,n) of the resulting poly(EMO)s was in the range of 1,3.3 × 105. The polymerization system was found to involve electron spin resonance (ESR) observable propagating poly(EMO) radicals under practical polymerization conditions. ESR-determined rate constants of propagation (kp) and termination (kt) at 60 °C are 120 and 2.41 × 105 L/mol s, respectively,much lower than those of the usual methacrylate esters such as methyl methacrylate and glycidyl methacrylate. The radical copolymerization of EMO (M1) with styrene (M2) at 60 °C gave the following copolymerization parameters: r1 = 0.53, r2 = 0.43, Q1 = 0.87, and e1 = +0.42. EMO was also observed to be polymerized by BF3OEt2 as the cationic initiator through the opening of the oxetane ring. The M,n of the resulting polymer was in the range of 650,3100. The cationic polymerization of radically formed poly(EMO) provided a crosslinked polymer showing distinguishably different thermal behaviors from those of the radical and cationic poly(EMO)s. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1269,1279, 2001 [source] Glass-Transition Temperature (Tg) of Free-Radically Prepared Polyacrylonitrile by Inverse Gas Chromatography, 2,.MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 17 2002Molecular-Weight Dependence of Tg of Two Different Types of Aqueous Polymers Abstract The molecular-weight dependence of the glass-transition temperature (Tg) of a series of atactic polyacrylonitriles (PAN)s was studied by inverse gas chromatographic (IGC) analysis. PANs having different molecular weights were prepared by either; (i) the addition of isopropyl alcohol as a chain-transfer agent, or (ii) a scission reaction induced by the addition of alkali (NaOH) to a solution (N,N -dimethylformamide solution, at 25,°C) of the resulting polymer. The intrinsic viscosity [,] was in the range of 10.9,0.1 (dl,·,g,1), which corresponds to a viscosity-averaged molecular weight (Mv) of 1,590,000,3,000. As part of the results, a side reaction, which saw the conversion of the nitrile (CN) groups of PAN into amide (CONH2) and/or carboxylic acids (COOH) groups by alkali, was found to occur. The typical molecular-weight dependence of the Tg in free-radically prepared PAN was discussed in connection with a chain-transfer mechanism in an aqueous medium. Molecular-weight dependence of the Tg for PAN (WA). An error bar is given by a short vertical arrow. [source] Synthesis and Controlled Polymerisation of a Novel Gramicidin S AnalogueMACROMOLECULAR RAPID COMMUNICATIONS, Issue 16 2005Lee Ayres Abstract Summary: The controlled polymerisation of a bulky, peptide-based monomer was investigated. The cyclic , -sheet forming decapeptide gramicidin S was modified with a methacrylate handle and subsequently polymerised via atom transfer radical polymerisation (ATRP), to yield a well-defined gramicidin-S-containing polymer. The secondary structure of the peptide moiety was retained within the resulting polymer, as indicated by IR spectroscopy. This is the first example of the use of ATRP to create a synthetic polymer with a cyclic peptide as a side chain. The gramicidin S based monomers synthesised here were then polymerised by ATRP. [source] The Quenched Instationary Polymerization Systems (QUIPS)MACROMOLECULAR THEORY AND SIMULATIONS, Issue 2-3 2003Irene Schnöll-Bitai Abstract The common element of quenched instationary polymerization systems is that at a given time all radicals present are deactivated by an efficient and fast quench reaction. Quenched instationary polymerizations can be carried out in a variety of ways distinguished by the way periods differing in their initiation characteristics are combined. The total chain length distribution of the resulting polymer is always the sum of the quenched radical and polymer chain length distribution. This distribution is either completely or at least partially dominated by the contribution of the quenched radical spectrum. Depending on the experimental conditions monomodal or multimodal distributions are obtained which can be characterized by their extrema (maximum, points of inflection) and peak widths (absolute, relative). The location of the extrema are related to the experimental parameters and can be used in an unambiguous way for the direct determination of the rate constant of propagation. Absolute peak widths (defined as the difference between two succeeding points of inflection) are invariant quantities with respect to the number, molar mass and hyper distribution which is only true for Poisson (and narrow Gauss) distributions. Relative peak widths are a valuable tool for the direct determination of axial dispersion which occurs in size exclusion chromatography. Comparison of experimental and ideal relative peak widths can be used for the direct determination of the axial dispersion. The influence of the type of termination and [R0] (termination by combination) on the total (number) chain length distribution for single , -pulse initiation. [source] Nanofabrication of aligned conducting polymers,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9-10 2006Muge Acik Abstract Poly(pyrrole), poly(N-methyl pyrrole), poly(thiophene) and poly(3,4-ethylenedioxythiophene) nano-arrays, nano-fibers and nano-tubes have been successively synthesized using polycarbonate and alumina membranes as templates. Oxidative chemical polymerization method was used to produce nano-structured conducting polymers with diameters in the range of 80,350 nm and the size of the resulting polymer was controlled with the pore size of membrane. Preliminary results showed that highly oriented polymers are promising materials for many applications including supercapacitors, sensors and photonic devices. Copyright © 2006 John Wiley & Sons, Ltd. [source] Homolysis of N -alkoxyamines: A Computational StudyCHEMPHYSCHEM, Issue 2 2006Anouk Gaudel-Siri Dr. Abstract During nitroxide-mediated polymerization (NMP) in the presence of a nitroxide R2(R1)NO., the reversible formation of N -alkoxyamines [PON(R1)R2] reduces significantly the concentration of polymer radicals (P.) and their involvement in termination reactions. The control of the livingness and polydispersity of the resulting polymer depends strongly on the magnitude of the bond dissociation energy (BDE) of the CON(R1)R2bond. In this study, theoretical BDEs of a large series of model N -alkoxyamines are calculated with the PM3 method. In order to provide a predictive tool, correlations between the calculated BDEs and the cleavage temperature (Tc,), and the dissociation rate constant (kd,), of the N -alkoxyamines are established. The homolytic cleavage of the NOC bond is also investigated at the B3P86/6-311++G(d,p)//B3LYP/6-31G(d), level. Furthermore, a natural bond orbital analysis is carried out for some N -alkoxyamines with a OCON(R1)R2fragment, and the strengthening of their CON(R1)R2bond is interpreted in terms of stabilizing anomeric interactions. [source] Synthesis, Photophysics and Morphology of a Conjugated Polymer with Azobenzene Building Block in the BackboneCHINESE JOURNAL OF CHEMISTRY, Issue 7 2010Dezhi Shen Abstract A conjugate polymer poly[p -(phenyleneethylene)-alt-(phenyleneazophenyleneethylene)] (PPEPAPE) containing azobenzene building block in the polymer backbone was synthesized via Sonogashira cross-coupling of 4,4,-diiodoazobenzene and 1,4-diethynyl-2,5-didodecyloxybenzene. All the monomers and the resulting polymer were well characterized. The polymer had a relatively high molecular weight and showed very good solubility (,10 mg/mL) in common organic solvents. The photophysics of this polymer in solution and in film was investigated. The surface morphology of the films was studied by scanning electron microscope (SEM) and the relationship between the morphology and absorbance was discussed. This polymer has good film-forming property, broad absorbance and no emission, which might make it a good candidate for the photovoltaic material in the solar cell. [source] The substituent effects on the structure and surface morphology of polyanilineJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Mutlu Sahin Abstract In this work, poly(2-fluoroaniline), poly(2-chloroaniline), poly(2-methylaniline), and poly(N -ethylaniline) were prepared by a self-assembly method using an oxidizing system consisting of a dopant anion, p-toluene sulfonate with ammonium peroxydisulfate. The effects of substituents on the surface morphology, conductivity, molecular weight, spectral and thermal properties of the polymers were studied. SEM results revealed that the surface morphology of the resulting polymers changed from nanofiber to spherical structure by changing the substituent on the aniline monomers. The structure and properties of these conducting films were characterized by FTIR, UV-vis, elemental analysis, TGA, conductivity, and cyclic voltammetry. The polymer films show electroactivity in monomer free solution. Molecular weight of the polymers was determined by gel permeation chromatography. The dry electrical conductivity values of the substituted-polyanilines were found to be lower than that of PANI. The results revealed that the molecular structures of the polymers were similar to those of the emeraldine form of polyaniline. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Free-radical copolymerization of 2,2,2-trifluoroethyl methacrylate and 2,2,2-trichloroethyl ,-fluoroacrylate: Synthesis, kinetics of copolymerization, and characterizationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2010Jean-Marc Cracowski Abstract Copolymers based on 2,2,2-trifluoroethyl methacrylate (MATRIFE) and 2,2,2-trichlororoethyl ,-fluoroacrylate (FATRICE) were synthesized in good yields by radical process initiated by tert -butyl 2,2-dimethylperoxypropanoate. Molar composition of the obtained poly(MATRIFE- co -FATRICE) copolymers were assessed by means of 1H and 19F nuclear magnetic resonance spectroscopy and by elemental analysis. The reactivity ratios, ri, of both comonomers were determined from the Kelen-Tüdos and Finneman-Ross methods (rMATRIFE = 1.52 ± 0.03 and rFATRICE = 0.61 ± 0.03 at 74 °C) showing unexpectedly that MATRIFE is the more reactive monomer in copolymerization. Molecular weights and polydispersity indexes of poly(MATRIFE- co -FATRICE) copolymers were ranging between 1.47 and 2.68 × 104 g·mol,1 and from 1.44 to 2.21, respectively. Thermal properties of the resulting polymers were examined and thermogravimetric analyses showed a satisfactory thermal stability, a thermal decomposition occurring from 220 to 295 °C as the molar ratio of FATRICE increased in the copolymer. Moreover, the glass transition temperatures of copolymers varied from 66 to 108 °C and also increased with FATRICE molar ratio in the copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2154,2161, 2010 [source] Asymmetric anionic polymerization of 7-cyano-7-ethoxycarbonyl-1,4-benzoquinone methideJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 21 2009Noboru Nakagaki An optically active polymer having configurational chirality in the main chain was synthesized from a prochiral monomer, 7-cyano-7-ethoxycarbonyl-1,4-benzoquinone methide (1), by asymmetric anionic polymerization using various chiral anionic initiators. The effects of the chiral ligand and solvent polarity on the specific rotations of the resulting polymers were investigated. The polymerization of 1 using iPrPhOLi/(,)-PhBox complex initiator in a mixture solution of dichloromethane/toluene ratio of 30/70 (in vol %) at ,78 °C afforded an optically active polymer with a large positive specific rotation ([,]435 = +90.4°). [source] Ultrafast SET-LRP of methyl acrylate at 25 °C in alcoholsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2008Gerard Lligadas Abstract Alcohols are known to promote the disproportionation of Cu(I)X species into nascent Cu(0) and Cu(II)X. Therefore, alcohols are expected to be excellent solvents that facilitate the single-electron transfer mediated living radical polymerization (SET-LRP) mediated by nascent Cu(0) species. This publication demonstrates the ultrafast SET-LRP of methyl acrylate initiated with bis(2-bromopropionyloxy)ethane and catalyzed by Cu(0)/Me6 -TREN in methanol, ethanol, 1-propanol, and tert -butanol and in their mixture with water at 25 °C. The structural analysis of the resulting polymers by a combination of 1H NMR and MALDI-TOF MS demonstrates the synthesis of perfectly bifunctional ,,,-dibromo poly(methyl acrylate)s by SET-LRP in alcohols. Moreover, this work provides an expansion of the list of solvents available for SET-LRP. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2745,2754, 2008 [source] Synthesis of silicon-bridged polythiophene derivatives and their applications to EL device materialsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2007Joji Ohshita Abstract Palladium-catalyzed oxidative homo-coupling of 2,6-bis(tributylstannyl)dithienosiloles with CuCl2 afforded poly(dithienosilole-2,6-diyl)s as novel polythiophene derivatives with intra-chain silicon bridges, which exhibited red-shifted UV absorption maxima by about 100 nm from those of the corresponding silole-free polythiophenes. Alternate copolymers also were prepared by palladium-catalyzed cross-coupling reactions of 2,6-dibromodithienosiloles with distannylthiophene or bithophene. These polymer films were applied to single and double-layered organic electroluminescence devices. It was found that some of the resulting polymers exhibited electroluminescence properties and emitted red light in EL devices with the structure of ITO/polymer/Mg-Ag. Introducing an electron-transporting Alq3 layer between the polymer film and the Mg-Ag cathode led to a remarkable improvement in the devices performance. An application of the copolymer to a field effect transistor was also studied. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4588,4596, 2007 [source] New ligands for the Fe(III)-mediated reverse atom transfer radical polymerization of methyl methacrylateJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 9 2006Gang Wang Abstract A series of (di)picolinic acids and their derivates are investigated as novel complexing tridentate or bidentate ligands in the iron-mediated reverse atom transfer radical polymerization of methyl methacrylate in N,N -dimethylformamide at 100 °C with 2,2,-azobisisobutyrontrile as an initiator. The polymerization rates and polydispersity indices (1.32,1.8) of the resulting polymers are dependent on the structures of the ligands employed. Different iron complexes may be involved in iron-mediated reverse atom transfer radical polymerization, depending on the type of acid used. 1H NMR spectroscopy has been used to study the structure of the resulting polymers. Chain-extension reactions have been performed to further confirm the living nature of this catalytic system. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2912,2921, 2006 [source] Novel synthesis of polyethylene,poly(dimethylsiloxane) copolymers with a metallocene catalystJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2004Andrés E. Ciolino Abstract Polyethylene,poly(dimethylsiloxane) copolymers were synthesized in solution from an ethylene monomer and an ,-vinyl poly(dimethylsiloxane) (PDMS) macromonomer at 363 and 383 K with EtInd2ZrCl2/methylaluminoxane as a catalyst. The copolymers obtained were characterized with Fourier transform infrared spectroscopy, 1H and 13C NMR, size exclusion chromatography, and differential scanning calorimetry. The rheological properties of the molten polymers were determined under dynamic shear flow tests at small-amplitude oscillations, whereas the physical arrangement of the phase domains was analyzed with scanning electron microscopy (SEM)/energy dispersive X-ray (EDX). The analysis of the catalyst activity and the resulting polymers supported the idea of PDMS blocks or chains grafted to polyethylene. The changes in the rheological behavior and the changes in the Fourier transform infrared and NMR spectra were in agreement with this proposal. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2462,2473, 2004 [source] Synthesis and characterization of block copolymers from 2-vinylnaphthalene by anionic polymerizationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 24 2002Faquan Zeng Abstract The anionic polymerization of 2-vinylnaphthalene (2VN) has been studied in tetrahydrofuran (THF) at ,78 °C and in toluene at 40 °C. 2VN polymerization in THF, toluene, or toluene/THF (99:1 v/v) initiated by sec -butyllithium (sBuLi) indicates living characteristics, affording polymers with predefined molecular weights and narrow molecular weight distributions. Block copolymers of 2VN with methyl methacrylate (MMA) and tert -butyl acrylate (tBA) have been synthesized successfully by sequential monomer addition in THF at ,78 °C initiated by an adduct of sBuLi,LiCl. The crossover propagation from poly(2-vinylnaphthyllithium) (P2VN) macroanions to MMA and tBA appears to be living, the molecular weight and composition can be predicted, and the molecular weight distribution of the resulting block copolymer is narrow (weight-average molecular/number-average molecular weight < 1.3). Block copolymers with different chain lengths for the P2VN segment can easily be prepared by variations in the monomer ratios. The block copolymerization of 2VN with hexamethylcyclotrisiloxane also results in a block copolymer of P2VN and poly(dimethylsiloxane) (PDMS) contaminated with a significant amount of homo-PDMS. Poly(2VN- b -nBA) (where nBA is n -butyl acrylate) has also been prepared by the transesterification reaction of the poly(2VN- b -tBA) block copolymer. Size exclusion chromatography, Fourier transform infrared, and 1H NMR measurements indicate that the resulting polymers have the required architecture. The corresponding amphiphilic block copolymer of poly(2VN- b -AA) (where AA is acrylic acid) has been synthesized by acidic hydrolysis of the ester group of tert -butyl from the poly(2VN- b -tBA) copolymer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4387,4397, 2002 [source] Radical polymerization behavior of ethyl ortho -(4-phenyl-1,3-dioxolan-2-yl)phenyl fumarateJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2002Makiko Seno Abstract The polymerization of ethyl ortho -(4-phenyl-1,3-dioxolan-2-yl)phenyl fumarate (EPDPF) with dimethyl 2,2,-azobisisobutyrate (MAIB) was kinetically investigated in benzene. The polymerization rate (Rp) at 60 °C was presented by Rp = k[MAIB]1.1[EPDPF]0.8. The number-average molecular weight of poly(EPDPF) was in the range of 2500,3500. Analysis of 1H and 13C NMR spectra of the resulting polymers suggested that the radical polymerization of EPDPF proceeds in a complicated manner involving vinyl addition, intramolecular hydrogen abstraction, and ring opening of the cyclic acetal. The polymerization system involved electron spin resonance (ESR)-observable poly(EPDPF) radicals under the practical polymerization conditions. ESR-determined apparent rate constants (2.0,8.5 L/mol s) of propagation increased with increasing initiator concentration and decreasing monomer concentration. The apparent rate constants (0.68,6.6 × l06 L/mol s) of termination decreased with the monomer concentration and slightly increased with the initiator concentration. The activation energies of initiation (Ei), propagation (Ep), and termination (Et) were calculated as Ei = 158, Ep = 41, and Et = 30 kJ/mol, respectively. Radical copolymerization of EPDPF with styrene was also examined at 70 °C in benzene. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2945,2955, 2002 [source] Synthesis and polymerization of new styryl and methacryloyl monomers containing acidic saccharide moietiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2001Yoshiaki Shimura Abstract New styryl-type water-insoluble and methacryloyl-type water-soluble monomers, N -(p -vinylbenzyl)-1,2- O -isopropylidene-6- D -glucofuranuronamide and N -(2-methacryloylamino)ethyl-1,2- O -isopropylidene-6- D -glucofuranuronamide, were synthesized from the most common acidic saccharide, D -glucuronic acid. Their radical homopolymerizations and copolymerizations with styrene and acrylamide were tried under various conditions. The isopropylidene groups in the resulting polymers were removed in a mixture of trifluoroacetic acid and water (2/1 v/v) to give the corresponding polymers with many pendant D -glucopyranuronyl groups with reactive reducing groups. The pendant reducing ends may be useful as potential binding sites under a hydrophilic atmosphere. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3893,3901, 2001 [source] Synthesis and characterization of novel crosslinkable polymers with a nonlinear optical chromophore as a pendant groupJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2001Sung-Ho Jin Abstract New crosslinkable polymers with a nonlinear optical (NLO) active chromophore as a pendant group were synthesized by condensation chain polymerization via palladium-catalyzed carbon,carbon coupling reactions. The polymerization yields were almost quantitative between the diiodobenzene (DIB) and diethyldipropargyl malonate (DEDPM) or 4-(dimethylamino)-4,-(6-dipropargylacetoxypropylsulfonyl)stilbene (DASS-6) monomers. To improve the molecular weight and mechanical properties of the NLO active polymer, we carried out the copolymerization with DIB and DASS-6 with various feed ratios of DEDPM. The resulting polymers were soluble in organic solvents and spun-cast onto indium tin oxide-coated glass substrates to make thin films. The molecular structures of the resulting polymers were characterized with various instrumental methods to confirm the carbon,carbon coupling reactions between the DIB and diacetylene monomers. The absorption of the ultraviolet,visible spectrum of the resulting polymers was drastically reduced after thermal curing at 160 °C because of the crosslinking of the reactive acetylene group in the polymer backbone. The electrooptic coefficient (r33) measured at 1.3 ,m ranged from 7 to 15 pm/V. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4025,4034, 2001 [source] Lipase-Catalyzed Ring-Opening Polymerization of Molecularly Pure Cyclic Oligomers for Use in Synthesis and Chemical Recycling of Aliphatic PolyestersMACROMOLECULAR BIOSCIENCE, Issue 6 2008Asato Kondo Abstract The lipase-catalyzed ROP of molecularly pure cyclic oligomers with a definite degree of oligomerization is analyzed with respect to the molecular weights of the resulting polymers and certain kinetic parameters of the enzymatic reaction. Cyclic BA dimers, trimers, and tetramers polymerize faster than the equivalent monomer; however, the latter produces PBA of significantly higher molecular weight. The reason is that the ring opening of the cyclic monomer is slow, leading to a lower initiator concentration than that produced by the cyclic BA dimer and trimer. Similarly, the cyclic BS dimer produces PBS of higher molecular weight than that obtained from the cyclic BS trimer. [source] Synthesis and properties of new aromatic poly(ester-imide)s derived from 4- p -biphenyl-2,6-bis(4-trimellitimidophenyl) pyridine and various dihydroxy compoundsPOLYMER INTERNATIONAL, Issue 1 2007Hossein Behniafar Abstract A novel class of wholly aromatic poly(ester-imide)s, having a biphenylene pendant group, with inherent viscosities of 0.32,0.49 dL g,1 was prepared by the diphenylchlorophosphate-activated direct polyesterification of the preformed imide-ring-containing diacid, 4- p -biphenyl-2,6-bis(4-trimellitimidophenyl)pyridine (1) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. A reference diacid, 2,6-bis(trimellitimido)pyridine (2) without a biphenylene pendant group and two phenylene rings in the backbone, was also synthesized for comparison purposes. At first, with due attention to structural similarity and to compare the characterization data, a model compound (3) was synthesized by the reaction of compound 1 with two mole equivalents of phenol. Moreover, the optimum condition of polymerization reactions was obtained via a study of the model compound synthesis. All of the resulting polymers were characterized by Fourier transform infrared and 1H NMR spectroscopy and elemental analysis. The ultraviolet ,max values of the poly(ester-imide)s were also determined. All of the resulting polymers exhibited excellent solubility in common organic solvents, such as pyridine, chloroform, tetrahydrofuran, and m -cresol, as well as in polar organic solvents, such as N -methyl-2-pyrrolidone, N,N -dimethylacetamide, N,N -dimethylformamide, and dimethyl sulfoxide. The crystalline nature of the polymers obtained was evaluated by means of wide-angle X-ray diffraction. The resulting poly(ester-imide)s showed nearly an amorphous nature, except poly(ester-imide) derived from 4,4,-dihydroxy biphenyl. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry thermograms were in the range 298,342 °C. The 10% weight loss temperatures (T10%) from thermogravimetric analysis curves were found to be in the range 433,471 °C in nitrogen. Films of the polymers were also prepared by casting the solutions. Copyright © 2006 Society of Chemical Industry [source] New soybean oil-Styrene-Divinylbenzene thermosetting copolymers,IV.POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 6 2002Good damping properties Abstract New polymeric materials have been prepared by the cationic copolymerization of regular soybean oil, low saturation soybean oil, i.e. LoSatSoy oil, or conjugated LoSatSoy oil with styrene and divinylbenzene, norbornadiene or dicyclopentadiene initiated by boron trifluoride diethyl etherate (BF3·OEt2) or related modified initiators. The effects of the stoichiometry, the type of soybean oil and the alkene comonomer on the damping behavior of the resulting polymers have been investigated. The damping properties have been quantitatively evaluated by the loss tangent maximum (tan ,)max, the temperature range ,T for efficient damping (tan ,,>,0.3), and the integrals of the linear tan , v. temperature curves (tan , area, TA). These bulk materials are composed primarily of soybean oil-styrene-divinylbenzene random copolymers with considerable variability in the backbone compositions. The good damping properties of the soybean oil polymers are presumably determined by the presence of fatty acid ester side groups directly attached to the polymer backbone and the segmental heterogeneities resulting from crosslinking. In general, crosslinking reduces the (tan ,)max and the TA values, but broadens the region of efficient damping (,T). Soybean oil polymeric materials with appropriate compositions and crosslink densities are capable of efficiently damping over a temperature region in excess of 110,°C and provide noise and vibration attenuation over broad temperature and frequency ranges. Copyright © 2002 John Wiley & Sons, Ltd. [source] Electroactive Linear,Hyperbranched Block Copolymers Based on Linear Poly(ferrocenylsilane)s and Hyperbranched Poly(carbosilane)sCHEMISTRY - A EUROPEAN JOURNAL, Issue 36 2009Frederik Wurm Dipl.-Chem. Abstract A convenient two-step protocol is presented for synthesis of linear-hyperbranched diblock copolymers consisting of a linear, organometallic poly(ferrocenylsilane) (PFS) block and hyperbranched poly(carbosilane) (hbPCS) segments. Linear PFS diblock copolymers were synthesized through photolytic ring-opening polymerization of dimethyl[1]silaferrocenophane as the first block and methylvinyl[1]silaferrocenophane as the second. These block copolymers served as polyfunctional cores in a subsequent hydrosilylation polyaddition of different silane-based AB2 monomers. Three AB2 monomers (methyldiallylsilane; methyldiundecenylsilane, and ferrocenyldiallylsilane) were investigated; they introduced structural diversity to the hyperbranched block and showed variable reactivity for the hydrosilylation reaction. In the case with the additional ferrocene moiety in the ferrocenyldiallylsilane monomer, an electroactive hyperbranched block was generated. No slow monomer addition was necessary for molecular-weight control of the hyperbranching polyaddition, as the core had much higher functionality and reactivity than the carbosilane monomers. Different block ratios were targeted and hybrid block copolymers with narrow polydispersity (<1.2) were obtained. All the resulting polymers were investigated and characterized by size exclusion chromatography, NMR spectroscopy, cyclic voltammetry, and TEM, and exhibited strongly anisotropic aggregation. [source] | |||||||||||||