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Dong Jin Yoo - One of the best experts on this subject based on the ideXlab platform.

Takaki Kanbara - One of the best experts on this subject based on the ideXlab platform.

  • direct arylation Polycondensation for the synthesis of bithiophene based alternating copolymers
    Polymer Chemistry, 2013
    Co-Authors: Junpei Kuwabara, Yohei Fujinami, Yuta Nohara, Seong Jib Choi, Ken Yoshimura, Jun Oguma, Katsuhiro Suenobu, Takaki Kanbara
    Abstract:

    Direct arylation Polycondensation Reactions using a simple catalytic system gave eight kinds of bithiophene-based alternating copolymers. The conditions for the Reactions of 3,3′,4,4′-tetramethylbithiophene with dibromoarylenes were optimized to obtain high-molecular-weight polymers without formation of cross-linked structures. In the Reaction of a dibromoarylene containing a reactive C–H bond, a short Reaction time (1.5 h) was suitable for preventing side Reactions. In contrast, a long Reaction time (6 h) gave high-molecular-weight polymers from dibromoarylene monomers without a reactive C–H bond. This Polycondensation Reaction enables the synthesis of polymers containing dye structures such as diketopyrrolopyrrole and isoindigo, which are applicable as materials for polymer solar cells.

  • detailed optimization of Polycondensation Reaction via direct c h arylation of ethylenedioxythiophene
    Macromolecular Rapid Communications, 2013
    Co-Authors: Koutarou Yamazaki, Junpei Kuwabara, Takaki Kanbara
    Abstract:

    The Polycondensation Reaction of 3,4-ethylenedioxythiophene with 2,7-dibromo-9,9-dioctylfluorene via Pd-catalyzed direct arylation gives poly[(3,4-ethylenedioxythiophene-2,5-diyl)-(9,9-dioctylfluorene-2,7-diyl)]. The Reaction conditions are optimized in terms of the Pd precatalysts, Reaction time, and carboxylic acid additives. The combination of 1 mol% Pd(OAc)(2) and 1-adamantanecarboxylic acid as an additive is the optimized catalytic system, and it yields the corresponding polymer with a molecular weight of 39,400 in 89% yield. The Polycondensation Reaction, followed by an end-capping Reaction, effectively provides a linear polymer without Br terminals.

  • synthesis of thiophene and bithiophene based alternating copolymers via pd catalyzed direct c h arylation
    ACS Macro Letters, 2012
    Co-Authors: Yohei Fujinami, Junpei Kuwabara, Hideki Hayashi, Takaki Kanbara
    Abstract:

    Polycondensation via direct C–H arylation of thiophene derivatives gave thiophene- and bithiophene-based alternating copolymers in good yields. The optimization of the Reaction conditions was investigated in terms of a catalytic system and Reaction time. Under optimized conditions, the Polycondensation Reaction of 3,3′,4,4′-tetramethylbithiophene with 2,7-dibromo-9,9-dioctylfluorene gave poly[2,7-(9,9-dioctylfluorene)-alt-5,5′-(3,3′,4,4′-tetramethyl-2,2′-bithiophene)] with a molecular weight of 31 800 in 91% yield. The Polycondensation Reaction proceeded with 2 mol % of Pd(OAc)2 without the addition of a phosphine ligand in a short Reaction time (3 h). Six kinds of π-conjugated polymers were synthesized by the Polycondensation Reaction without the use of bifunctional organometallic reagents as monomers.

Kyu Ha Lee - One of the best experts on this subject based on the ideXlab platform.

Yury Gogotsi - One of the best experts on this subject based on the ideXlab platform.

  • interaction of polar and nonpolar polyfluorenes with layers of two dimensional titanium carbide mxene intercalation and pseudocapacitance
    Chemistry of Materials, 2017
    Co-Authors: Muhammad Boota, Mariacecilia Pasini, Francesco Galeotti, William Porzio, Mengqiang Zhao, Joseph Halim, Yury Gogotsi
    Abstract:

    This article provides insight into the interaction of synthetic conjugated polymers [polyfluorene derivatives (PFDs)] with layers of two-dimensional titanium carbide (Ti3C2Tx). Three derivatives with nonpolar, polar, and charged nitrogen-containing functionalities were synthesized via the Suzuki Polycondensation Reaction. The organic–inorganic PFD/Ti3C2Tx hybrids were prepared and characterized using X-ray diffraction and a range of microscopic and spectroscopic techniques to elucidate the host–guest interaction mechanism. We show that polar polymers with charged nitrogen-containing ends have the strongest interaction with the Ti3C2Tx layers, yielding an increase in interlayer spacing and large shifts in spectroscopic peaks. Furthermore, the effect of polymer backbone juxtaposition between Ti3C2Tx layers on pseudocapacitance is discussed in detail. Our results suggest that new organic materials capable of intercalation between the layers of Ti3C2Tx and other MXenes may be used in the design of hybrid stru...

  • Interaction of Polar and Nonpolar Polyfluorenes with Layers of Two-Dimensional Titanium Carbide (MXene): Intercalation and Pseudocapacitance
    2017
    Co-Authors: Muhammad Boota, Mariacecilia Pasini, Francesco Galeotti, William Porzio, Mengqiang Zhao, Joseph Halim, Yury Gogotsi
    Abstract:

    This article provides insight into the interaction of synthetic conjugated polymers [polyfluorene derivatives (PFDs)] with layers of two-dimensional titanium carbide (Ti3C2Tx). Three derivatives with nonpolar, polar, and charged nitrogen-containing functionalities were synthesized via the Suzuki Polycondensation Reaction. The organic–inorganic PFD/Ti3C2Tx hybrids were prepared and characterized using X-ray diffraction and a range of microscopic and spectroscopic techniques to elucidate the host–guest interaction mechanism. We show that polar polymers with charged nitrogen-containing ends have the strongest interaction with the Ti3C2Tx layers, yielding an increase in interlayer spacing and large shifts in spectroscopic peaks. Furthermore, the effect of polymer backbone juxtaposition between Ti3C2Tx layers on pseudocapacitance is discussed in detail. Our results suggest that new organic materials capable of intercalation between the layers of Ti3C2Tx and other MXenes may be used in the design of hybrid structures for high-performance energy storage applications and beyond

Khalil Faghihi - One of the best experts on this subject based on the ideXlab platform.

  • New Polyamides Derived from 2,5-Bis[(4-carboxyanilino) carbonyl] Pyridine and Hydantoin Derivatives: Synthesis and Characterization
    2016
    Co-Authors: Turk J Chem, Khalil Faghihi, Zohreh Mozaffari
    Abstract:

    We synthesized 2,5-bis[(4-carboxyanilino) carbonyl] pyridine (4) as a new monomer containing pyridyl moiety by using a 2-step Reaction. At first 2,5-pyridine dicarboxylic acid (1) was converted to 2,5-pyridine dicarbonyl dichloride (2). Then, diacid 4 was prepared by a condensation Reaction of diacid chloride (2) with p-aminobenzoic acid (3). Then, 6 new polyamides (6a-f) were synthesized through the Polycondensation Reaction of 2,5-bis[(4-carboxyanilino) carbonyl] pyridine (4) with 6 different derivatives of hydantoins (5a-f) in a medium consisting of N-methyl-2-pyrrolidone, triphenyl phosphite, calcium chloride, and pyridine. The Polycondensation Reaction produced a series of novel polyamides containing pyridyl moiety in the main chain in high yield, with inherent viscosities between 0.64 and 1.50 dL g−1. The resulting polymers were fully characterized by means of FT-IR spectroscopy, elemental analysis, inherent viscosity, and solubility tests. Thermal properties of these polymers were investigated using thermal gravimetric analysis (TGA) and differential thermal gravimetry (DTG). All the polymers were soluble at room temperature in polar solvents such as N,N′-dimethylaceamide, N,N′-dimethyl formamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone. Key Words: Polyamides, pyridyl moiety, hydantoin derivatives, direct Polycondensation

  • Preparation and characterization of new poly(amide–imide) reinforced layer silicate nanocomposite containing N,N′-pyrromellitoyl-bis-l-phenyl acetic acid
    Elsevier, 2014
    Co-Authors: Khalil Faghihi, Javad Pournajaf, Mohsen Hajibeygi
    Abstract:

    Two new samples of poly(amide–imide)/montmorillonite reinforced nanocomposites containing N,N′-pyrromellitoyl-bis-l-phenyl acetic acid moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide–imide) (PAI) 3 as a source of polymer matrix was synthesized by the direct Polycondensation Reaction of N,N′-pyrromelitoyl-bis-l-phenyl acetic acid 1 with 4,4′-diamino diphenyl ether 2 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PAI-nanocomposite films 4a and 4b with 10% and 20% silicate particles were characterized by FTIR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposite films were investigated by using UV–vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements

  • BASED ON BIS(4-CARBOXYPHENYL)-N,N'-PYROMELLITIMIDE ACID
    2011
    Co-Authors: Khalil Faghihi, Ali Asghari, Mohsen Hajibeygi
    Abstract:

    ABSTRACT. Two new poly(amide-imide)-montmorillonite reinforced nanocomposites containing bis(4-carboxyphenyl)-N,N'-pyromellitimide acid moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) as a source of polymer matrix was synthesized by the direct Polycondensation Reaction of bis(4-carboxyphenyl)-N,N'-pyromellitimide acid with 4,4'-diamino diphenyl sulfone in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PAI-nanocomposite films with 10 and 20 % silicate particles were characterized by FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nanocomposites films were investigated by using UV-Vis spectroscopy, thermal gravimetry analysis (TGA) and water uptake measurements

  • photosensitive and optically active poly amide imide s based on n n pyromellitoyl bis l amino acid and dibenzalacetone moiety in the main chain synthesis and characterization
    Journal of Macromolecular Science Part A, 2009
    Co-Authors: Khalil Faghihi, Mohsen Hajibeygi, Meisam Shabanian
    Abstract:

    Six new photosensitive and optically active poly(amide-imide)s (PAIs) with good inherent viscosities based on N,N′-(pyromellitoyl)-bis-L-amino acid and dibenzalacetone moiety in the main chain were synthesized from the direct Polycondensation Reaction of N,N-(pyromellitoyl)-bis-L-amino acids 3a–f with 2,5-bis(4-aminobenzylidene)cyclopentanone 7 by two different methods such as direct Polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride (CaCl2)/pyridine (py) and direct Polycondensation in a tosyl chloride (TsCl)/pyridine (py)/N,N-dimethylformamide (DMF) system. Also, 2,5-bis(4-aminobenzylidene)cyclopentanone 7 was synthesized by using a two-step Reaction. The polymerization Reactions produced a series of photosensitive and optically active PAIs with high yield and good inherent viscosity. The resulted polymers were fully characterized by means of FTIR and 1H-NMR spectroscopy, elemental analyses, inherent viscosity, specific rotation, solubility ...

  • new optically active poly amide imide s based on n n pyromellitoyl bis l amino acid and 1 3 bis 4 aminophenoxy propane synthesis and characterization
    Journal of Applied Polymer Science, 2008
    Co-Authors: Khalil Faghihi
    Abstract:

    Five new poly(amide-imide)s 8a-e were synthesized through the direct Polycondensation Reaction of five chiral N,N'-(pyromellitoyl)-bis-L-amino acids 3a-e with 1,3-bis(4-aminophenoxy) propane 7 in a medium consisting of N-methyl-2-pyrrolidone, triphenyl phosfite, calcium chloride, and pyridine. The Polycondensation Reaction produced a series of novel poly(amide-imide)s containing trimethylene moiety in the main chain in high yield with inherent viscosities between 0.34 and 0.65 dL/g. The resulted polymers were fully characterized by means of FTIR spectroscopy, elemental analyses, inherent viscosity, and solubility tests. Thermal properties of these polymers were investigated by using thermal gravimetric analysis (TGA) and differential thermal gravimetric (DTG). All of the polymers were soluble at room temperature in polar solvents such as N,N-dimethyl acetamide, N,N-dimethyl formamide, dimethyl sulfoxide, and N-methyl-2-pyrrolidone. N,N'-(pyromellitoyl)-bis-L-amino acids 3a-e were prepared in quantitative yields by the condensation Reaction of pyromellitic dianhydride (1,2,4,5-benzenetetracarboxylic acid 1,2,4,5-dianhydide) 1 with L-alanine 2a, L-valine 2b, L-leu-cine 2c, L-isoleucine 2d, and L-phenyl alanine 2e in acetic acid. Also l,3-bis(4-aminophenoxy) propane 7 was synthesized by using a two-step Reaction. At first 1,3-bis(4-nitrophenoxy) propane 6 was prepared from the Reaction of 4-nitrophenol 4 with 1,3-dibromoprapane 5 in NaOH solution. Then, dinitro compound 6 was reduced by using Na 2 S.