scholarly journals Poly(Arylene Ether Sulfone)s with HEPES Pendants: Synthesis, Thermal, and Dielectric Studies

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
S. D. Ganesh ◽  
M. N. K. Harish ◽  
B. J. Madhu ◽  
Husnasarvari Maqbool ◽  
K. V. Pai ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Carboxylic Acid ◽  
Acid Group ◽  
Electrical Contacts ◽  
Stoichiometric Ratio ◽  
Coupling Condition ◽  
Arylene Ether ◽  
Modified Polymers ◽  
Nucleophilic Displacement ◽  
Ft Ir

Polyethersulfone with active carboxylic acid pendants was prepared from solution polymerization via nucleophilic displacement polycondensation reaction among 4,4′-dichlorodiphenyl sulfone (DCDPS) and 4,4′-bis(4-hydroxyphenyl) valeric acid (BHPA). The conditions necessary to synthesize and purify the polymer were investigated in some details. The synthesized polyethersulfone comprises sulfone and ether linkages in addition to reactive carboxylic acid functionality; this reactive carboxylic acid group was exploited to hold the HEPES moiety via ester linkage and is achieved by simple DCC coupling condition at ambient temperature. Without impairing the primary polymeric backbone, three modified polymers were prepared by varying the stoichiometric ratio of HEPES. Characterization of the polymers by 1H & 13C NMR, FT-IR, and TGA demonstrated that HEPES was quantitatively incorporated into the prime polymer. All the prepared polymers were pressed into tablets, and electrical contacts were established to study the dielectric properties. Finally, the influence of the HEPES on the dielectric properties was examined.

scholarly journals Functional Aromatic Poly(1,3,4-Oxadiazole-Ether)s with Benzimidazole Pendants: Synthesis, Thermal and Dielectric Studies

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shimoga D. Ganesh ◽  
Vasantakumar K. Pai ◽  
Mahadevappa Y. Kariduraganavar ◽  
Madhu B. Jayanna
Keyword(s):  
Carboxylic Acid ◽  
Average Molecular Weight ◽  
Analytical Techniques ◽  
Gel Permeation Chromatography ◽  
Electrical Contacts ◽  
Dielectric Studies ◽  
Weight Average Molecular Weight ◽  
Nucleophilic Displacement ◽  
Ft Ir

Poly(1,3,4-oxadiazole-ether) with reactive carboxylic acid pendants was synthesized from solution polymerization via nucleophilic displacement polycondensation among 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazole (BFPOx) and 4,4′-bis(4-hydroxyphenyl) valeric acid (BHPA). Without altering the polymeric segments, benzimidazole modified poly(1,3,4-oxadiazole-ether)s were prepared by varying stoichiometric ratios of 1,2-phenylenediamine. The molecular structural characterization of these polymers was achieved by, FT-IR, NMR, TGA, elemental analysis, and analytical techniques. The weight-average molecular weight of virgin polymer with carboxylic acid functionality was determined by gel permeation chromatography (GPC) and was found to be 22400 (Mw/Mn=2.07). All the synthesized polyethers were compressed into pellets and electrical contacts were established to perform dielectric properties.

scholarly journals Synthesis of bis-azobenzene derivatives with reactive bromohexyl unit and carboxylic acid group based on Disperse Yellow 7

2020 ◽  
Vol 11 (4) ◽  
pp. 298-303
Author(s):  
Alina Madalina Darabut ◽  
Olha Hennadiivna Purikova ◽  
Yevheniia Volodymyrivna Lobko
Keyword(s):  
Carboxylic Acid ◽  
Molecular Electronics ◽  
Azo Dye ◽  
Analytical Techniques ◽  
Acid Group ◽  
Carboxylic Acid Group ◽  
Acid Moiety ◽  
Ft Ir ◽  
Hydrolysis Of ◽  
Azobenzene Derivatives

In this work, two types of azobenzene derivatives based on Disperse Yellow 7 (DY7, 4-[4-(phenylazo)phenylazo]-o-cresol) were synthesized, which are bis-azobenzenes bearing flexible functional 6-bromohexyl chain or carboxylic acid moiety. The first one was synthesized by alkylation of DY7 with an excess of 1,6-dibromohexane in the presence of a mild base (K2CO3). The second one (azo dye with carboxylic acid functionality) was obtained by the alkaline hydrolysis of the ester bond of the newly obtained DY7 derivative with the ethoxycarbonyl group. The synthesized compounds were characterized by different spectral analytical techniques such as 1H NMR, 13C NMR, FT-IR, and UV-Vis. They can be employed for the synthesis of a wide variety of azo-based materials, which may be suitable for photochromic systems and molecular electronics applications.

scholarly journals Functionalized Poly(arylene ether nitrile) Porous Membrane with High Pb(II) Adsorption Performance

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1412 ◽  
Author(s):  
Xiaocan Liu ◽  
Meirong Zhou ◽  
Xuefei Zhou ◽  
Lingling Wang ◽  
Xiaobo Liu
Keyword(s):  
Carboxylic Acid ◽  
Acid Group ◽  
Lead Ions ◽  
Porous Membranes ◽  
Ammonium Bromide ◽  
Order Kinetic ◽  
Carboxylic Acid Group ◽  
Adsorption Performance ◽  
Arylene Ether ◽  
Adsorption Capacities

Porous materials with high specific surface area possess a broad application prospect in the treatment of wastewater. In this work, sulfonated poly(arylene ether nitrile) (SPEN) functionalized with a carboxylic acid group was successfully synthesized, which was subsequently transformed into SPEN porous membranes with cetyltrimethyl ammonium bromide (CTAB) as pore-forming agents to study the adsorption performance for lead ions in aqueous solution. Then, experiments were conducted to investigate the effect of pH, contact time and initial solution concentration on the adsorption performance of porous membranes, and the adsorption capacities of porous membranes with different content (0, 5 and 15 wt %) of CTAB were 183.60, 161.73 and 127.43 mg/g, respectively, which manifested that the adsorption capacity decreased with the increase of CTAB. The adsorption capacities of porous membranes increased with the increase of the initial concentration of lead ions, and the maximum reached was 246.96 mg/g. The simulation of adsorption kinetics revealed that the adsorption was accorded with the pseudo-second-order kinetic model and Langmuir equation, indicating that the adsorption process followed Langmuir monolayer adsorption. Thermogravimetric analysis demonstrated that the porous membranes had excellent thermodynamic properties both before and after adsorption. In addition, the change of adsorption peak in the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) spectrum indicated that the absorption performance of porous membranes for lead ions benefited from the chelation between lead ions and the carboxylic acid group on SPEN. Moreover, the porous membranes maintained excellent adsorption properties after circulating five times under the conditions of acidic or alkaline, and the cycle regeneration effect was outstanding.

scholarly journals Thermal and Dielectric Behavior Studies of Poly(Arylene Ether Sulfone)s with Sulfonated and Phosphonated Pendants

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Shimoga D. Ganesh ◽  
Vasantakumar K. Pai ◽  
Mahadevappa Y. Kariduraganavar ◽  
Madhu B. Jayanna
Keyword(s):  
Dielectric Properties ◽  
Carboxylic Acid ◽  
Sulfanilic Acid ◽  
Dielectric Behavior ◽  
Electrical Contacts ◽  
Sulphonic Acid ◽  
Valeric Acid ◽  
Synthetic Route ◽  
Polymer Backbone ◽  
Palladium Catalyzed

The present paper discusses the aspects of the synthesizing valeric acid based poly(ether sulfone)s with active carboxylic acid pendants (VALPSU) from solution polymerization technique via nucleophilic displacement polycondensation reaction among 4,4′-dichlorodiphenyl sulfone (DCDPS) and 4,4′-bis(4-hydroxyphenyl) valeric acid (BHPA). The conditions necessary to synthesize and purify the polymer were investigated in some detail. The synthesized poly(ether sulfone)s comprise sulfone and ether linkages in addition to reactive carboxylic acid functionality; these active carboxylic acid functional groups were exploited to hold the phenyl sulphonic acid and phenyl phosphonic acid pendants. The phenyl sulphonic acid pendants in VALPSU were easily constructed by altering active carboxylic acid moieties by sulfanilic acid using N,N′-dicyclohexylcarbodiimide (DCC) mediated mild synthetic route, whereas the latter one was built in two steps. Initially, polyphosphoric acid condensation with VALPSU by 4-bromoaniline and next straightforward palladium catalyzed synthetic route, in both of which acidic pendants are clenched by polymer backbone via amide linkage. Without impairing the primary polymeric backbone modified polymers were prepared by varying the stoichiometric ratios of respective combinations. All the polymers were physicochemically characterized and pressed into tablets; electrical contacts were established to study the dielectric properties. Finally, the influence of the acidic pendants on the dielectric properties was examined.

Crystal structure of tofacitinib dihydrogen citrate (Xeljanz®), (C16H21N6O)(H2C6H5O7)

2021 ◽  
pp. 1-8
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Density Functional ◽  
Acid Group ◽  
Dimensional Network ◽  
Van Der Waals Contacts ◽  
Citrate Anion

The crystal structure of tofacitinib dihydrogen citrate (tofacitinib citrate) has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Tofacitinib dihydrogen citrate crystallizes in space group P212121 (#19) with a = 5.91113(1), b = 12.93131(3), c = 30.43499(7) Å, V = 2326.411(6) Å3, and Z = 4. The crystal structure consists of corrugated layers perpendicular to the c-axis. Within the layers, cation⋯anion and anion⋯anion hydrogen bonds link the fragments into a two-dimensional network parallel to the ab-plane. Between the layers, there are only van der Waals contacts. A terminal carboxylic acid group in the citrate anion forms a strong charge-assisted hydrogen bond to the ionized central carboxylate group. The other carboxylic acid acts as a donor to the carbonyl group of the cation. The citrate hydroxy group forms an intramolecular charge-assisted hydrogen bond to the ionized central carboxylate. Two protonated nitrogen atoms in the cation act as donors to the ionized central carboxylate of the anion. These hydrogen bonds form a ring with the graph set symbol R2,2(8). The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™ (PDF®).

scholarly journals Improving flexural and dielectric properties of carbon fiber epoxy composite laminates reinforced with carbon nanotubes interlayer using electrospray deposition

2020 ◽  
Vol 9 (1) ◽  
pp. 1170-1182
Author(s):  
Muhammad Razlan Zakaria ◽  
Hazizan Md Akil ◽  
Mohd Firdaus Omar ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Aslina Anjang Ab Rahman ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Properties ◽  
Carbon Fiber ◽  
Composite Laminates ◽  
Epoxy Composite ◽  
Flexural Modulus ◽  
X Ray Diffraction ◽  
Electrospray Deposition ◽  
Ft Ir ◽  
Carbon Fiber Epoxy

AbstractThe electrospray deposition method was used to deposit carbon nanotubes (CNT) onto the surfaces of woven carbon fiber (CF) to produce woven hybrid carbon fiber–carbon nanotubes (CF–CNT). Extreme high-resolution field emission scanning electron microscopy (XHR-FESEM), X-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the woven hybrid CF–CNT. The results demonstrated that CNT was successfully and homogenously distributed on the woven CF surface. Woven hybrid CF–CNT epoxy composite laminates were then prepared and compared with woven CF epoxy composite laminates in terms of their flexural and dielectric properties. The results indicated that the flexural strength, flexural modulus and dielectric constant of the woven hybrid CF–CNT epoxy composite laminates were improved up to 19, 27 and 25%, respectively, compared with the woven CF epoxy composite laminates.

Synthesis of N2, N6-bis(5-methylthiazol-2-yl)pyridine-2,6-dicarboxamide fluoroscent sensor for detection of Cu2+ and Ni2+ Ions

Drug Research ◽  
2021 ◽  
Author(s):  
Anuroop Kumar ◽  
Netrapal Singh ◽  
Mordhwaj Kumar ◽  
Uma Agarwal
Keyword(s):  
Spectral Analysis ◽  
Detection Limit ◽  
Metal Ions ◽  
1H Nmr Spectroscopy ◽  
Stoichiometric Ratio ◽  
Selective Detection ◽  
Ft Ir ◽  
Uv Visible ◽  
Complexes With Metal Ions ◽  
Competitive Ions

AbstractThis article reports an amide based Chemosensor used for selective detection of divalent Cu+2 and Ni+2 ions via Fluorescence turn off. The selective sensing ability of Chemosensor was investigated in presence of different metal ions Mg2+, Ag+, Fe2+, K+, Cu2+, Ni2+, Hg2+, Pb2+, Mn2+, Pd2+, Cd2+ and Mn3+ as competitive ions. The receptor i. e. Chemosensor formed complexes with metal ions in 1:1 stoichiometric ratio. The detection limit and binding constant calculated as 1.92×10–4 and 1.4×10–4 M and 2.16×103 M−1 and 3.09×103 M−1 for Cu2+ and Ni2+ions respectively. The complexes were characterized by UV/visible, FT-IR, 13C NMR and 1H NMR spectroscopy. Further the structure and Crystallinity were calculated by P-XRD spectral analysis. The crystallinity found to be 65.27 and 67.87% respectively

The inner salt 4-carboxy-2-(pyridinium-4-yl)-1H-imidazole-5-carboxylate monohydrate

2006 ◽  
Vol 62 (7) ◽  
pp. o2751-o2752 ◽  
Author(s):  
Ting Sun ◽  
Jian-Ping Ma ◽  
Ru-Qi Huang ◽  
Yu-Bin Dong
Keyword(s):  
Carboxylic Acid ◽  
Dihedral Angle ◽  
Title Compound ◽  
Acid Group ◽  
Planar Structure ◽  
Carboxyl Group ◽  
Carboxylic Acid Group ◽  
Pyridyl Group ◽  
Compound C

In the title compound, C10H7N3O4·H2O, one carboxyl group is deprotonated and the pyridyl group is protonated. The inner salt molecule has a planar structure, apart from the carboxylic acid group, which is tilted from the imidazole plane by a small dihedral angle of 7.3 (3)°.

Preparation and Properties of Silicon-Containing Arylacetylene Resins with Octa(maleimidophenyl)silsesquioxane

2012 ◽  
Vol 557-559 ◽  
pp. 1152-1156
Author(s):  
Yan Zhou ◽  
Fu Wei Huang ◽  
Fa Rong Huang ◽  
Lei Du
Keyword(s):  
Thermal Stability ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Thermal Polymerization ◽  
Curing Process ◽  
Thermal Stabilities ◽  
Curing Reaction ◽  
Air Atmosphere ◽  
Ft Ir ◽  
Dsc Analyses

Modified silicon-containing arylacetylene resins (DMSEPE-OMPS) were prepared from poly(dimethylsilyleneethynylenephenyleneethynylene) (DMSEPE) and Octa(maleimidophenyl)- silsesquioxane (OMPS). The curing reaction of DMSEPE-OMPS resin was studied by FT-IR and DSC techniques. Thermal stability and dielectric properties of cured DMSEPE-OMPS resins were determined. FT-IR and DSC analyses indicate that thermal polymerization of DMSEPE-OMPS resin occurs in the curing process. Thermal stabilities of cured DMSEPE-OMPS resins under N2 and air atmosphere decrease gradually with the increment of OMPS components. The incorporation of OMPS can obviously reduce dielectric constant of DMSEPE-OMPS resins.

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