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Mohammad Ali Karimi Zarchi - One of the best experts on this subject based on the ideXlab platform.
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diazotization cyanation of aromatic amines with crosslinked poly 4 vinylpyridine supported cyanide ions
Journal of Applied Polymer Science, 2012Co-Authors: Mohammad Ali Karimi Zarchi, Nahid EbrahimiAbstract:A simple, mild, and efficient method for the cyanation of stable arenediazonium salts was developed with polymer-supported cyanide. Arenediazonium hydrogen sulfate (ArN2+HSO4−) was obtained by the reaction between a primary aryl amine and sodium nitrite in the presence of concentrated sulfuric acid (H2SO4) at low temperature (0–5°C). By an ion-exchange reaction between ArN2+HSO4− and NaBF4, the stable arenediazonium tetrafluoroborate, ArN2+BF4−, was prepared. ArN2+BF4− was then converted to aryl nitrile with crosslinked poly(4-vinylpyridine) supported cyanide ion in acetonitrile at room temperature. The spent polymeric reagent was regenerated and reused several times without any loss in its activity. This procedure offered advantages, including a higher isolated yield, shorter reaction time, and simple reaction workup. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
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iodination of stable aromatic diazonium salt using crosslinked poly 4 vinylpyridine supported iodide
Journal of Applied Polymer Science, 2012Co-Authors: Mohammad Ali Karimi Zarchi, Nahid EbrahimiAbstract:An efficient and simple method for the iodination of stable arenediazonium salts has been developed by using a polymer-supported iodide. The arenediazonium chlorides, Ar-NCl−, were obtained by the reaction between primary aryl amine and sodium nitrite in the presence of concentrated hydrochloric acid (HCl) at low temperature (0–5°C). By ion exchange reaction between Ar-NCl− with NaBF4, the stable arenediazonium tetrafluoroborates, Ar-NBF, were prepared. Ar-NBF, were then converted to aryl iodides by crosslinked poly (4-vinylpyridine)-supported iodide, [P4-VP]I, in acetonitrile at room temperature. The spent polymeric reagent was regenerated and reused for several times without losing its activity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
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solvent free diazotization azidation of aryl amine using a polymer supported azide ion
Journal of Applied Polymer Science, 2012Co-Authors: Mohammad Ali Karimi Zarchi, Rahman NabaeiAbstract:Crosslinked poly (4-vinylpyridine)-supported azide ion was used as an effective azidating agent for deazodination of stable arenediazonium salts under solvent-free conditions in high yields. The diazotization of aromatic amines was prepared by grinding the combination of an aromatic amine, sodium nitrite (NaNO2), p-toluene sulfonic acid (p-TsOH), and 0.2 mL H2O in a mortar. Grinding was continued for deazodination–azidation of the obtained relatively stable diazonium salts, with addition of crosslinked poly (4-vinylpyridine) supported azide ion to obtain the corresponding aryl azides. The spent polymeric reagents can usually be removed and regenerated. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
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diazotization azidation of amines in water by using crosslinked poly 4 vinylpyridine supported azide ion
Journal of Applied Polymer Science, 2012Co-Authors: Mohammad Ali Karimi Zarchi, Rahman Nabaei, Saeed BaraniAbstract:The use of polymeric reagents simplifies routine azidation of diazonium salts, because it eliminates the traditional purification. An efficient, simple, and effective method for the preparation of aryl azides is described. The synthesis of aromatic azides from the corresponding amines is accomplished under mild conditions with sodium nitrite in the presence of p-toluenesulfonic acid or concentrated H2SO4 at low temperature (0–5°C to room temperature). The obtained relatively stable diazonium salts, followed by treatment with a polymer-supported azide ion in water at room temperature to produce the corresponding aryl azides. The spent polymeric reagents can be regenerated and reused for several times without losing their activity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
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Synthesis of S‐alkyl thiobenzoates from alkyl halides mediated by poly(4‐vinylpyridine) supported sodium thiobenzoate at room temperature under heterogeneous conditions
Journal of Applied Polymer Science, 2011Co-Authors: Mohammad Ali Karimi Zarchi, Mojgan NejabatAbstract:We describe the use of readily available crosslinked poly(4-vinylpyridine) supported sodium thiobenzoate, [P4VP]SCOPh, in the suspended solution phase synthesis of S-alkyl thiobenzoate at room temperature in high yields. The spent polymeric reagent can be removed quantitatively by filtration and pure products can be obtained by evaporation of the solvent. The spent polymeric reagent can be regenerated and reused for several times. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Gerard Riess - One of the best experts on this subject based on the ideXlab platform.
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Water dispersibility of non-aqueous emulsions stabilized and viscosified by a poly(butadiene)-poly(2-vinylpyridine)-poly(ethylene oxide) (PBut-P2VP-PEO) triblock copolymer
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2015Co-Authors: Leonard Ionut Atanase, Jean-philippe Lerch, Gerard RiessAbstract:Abstract Biocompatible non-aqueous emulsions, stabilized by a well-defined poly(butadiene)-poly(2-vinylpyridine)-poly(ethylene oxide) (PBut-P2VP-PEO) triblock copolymer, were developed for the system glycerine ester (Miglyol 812) dispersed in polyethylene glycol (PEG 400). One of the most attractive features of this copolymer is its capacity to form, by hydrogen bonding, thermoreversible micellar systems in PEG 400 with a thermal transition around 43 °C. Moreover, this transition was also observed in the case of a non-aqueous viscosified emulsion, with 30 vol% Miglyol 812 as dispersed phase. An original aspect of this type of emulsions, with a water-miscible PEG 400 continuous phase, is its water dispersibility at pH 1 and pH 7 without any additional surfactant. In fact, the initial non-aqueous emulsion is sterically stabilized and after water addition at pH 1 the copolymer provides a combination of steric and electro-steric stabilization due to the presence of the PEO sequences and of the protonated P2VP units. At pH 7, the stabilization is predominately achieved by the PEO and, to a lesser extent, by the collapsed P2VP sequences. The electro-steric stabilization at pH 1 is more efficient than the steric stabilization at pH 7.
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Stabilization of non-aqueous emulsions by poly(2-vinylpyridine)-b-poly(butadiene) block copolymers
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014Co-Authors: Leonard Ionut Atanase, Gerard RiessAbstract:Abstract Non-aqueous sub-micron biocompatible emulsions, which are of interest for biomedical and cosmetic formulations, were developed for the system polyethylene glycol (PEG 400) dispersed in a typical liquid glycerine ester (Miglyol 812). These emulsions were stabilized by poly(2-vinylpyridine)- b -poly(butadiene) (P2VP- b -PBut) copolymers, each of these sequences being well adapted to the solubility parameters of the two liquid phases. A comparative study of the emulsifying and stabilization efficiency was performed for two copolymers with quasi-identical molecular weights but of different compositions, such as P2VP 50 - b -PBut 128 ( A ) and P2VP 37 - b -PBut 189 ( B ). These block copolymers form in Miglyol 812 star-like micelles having a P2VP core and a PBut corona. The PEG 400/Miglyol 812 emulsion characteristics were determined as a function of the dispersed phase volume fractions and of the copolymer concentrations. At constant concentrations, copolymer B , with longer Miglyol 812 soluble PBut chains, appeared to be more efficient as emulsifier and stabilizer than copolymer A . By combination of the two block copolymer, a synergetic emulsifying and stabilizing effect could be achieved.
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PEG 400/Paraffin oil non‐aqueous emulsions stabilized by PBut‐Block‐P2VP block copolymers
Journal of Applied Polymer Science, 2014Co-Authors: Leonard Ionut Atanase, Gerard RiessAbstract:For the preparation of PEG 400 in paraffin oil non-aqueous biocompatible emulsions, the stabilization efficiency was compared for two well-defined poly(butadiene)-block-poly(2-vinylpyridine) (PBut-block-P2VP) block copolymers, with similar molecular weights but different compositions. The PBut128-block-P2VP50 and PBut189-block-P2VP37 samples, designated as copolymer A and B, respectively, are self-organized in paraffin oil as micelles with a P2VP core and a PBut corona. The PEG 400/paraffin oil emulsion characteristics were determined as a function of the copolymers concentrations and phase ratios. Higher static and shear stabilities were obtained for emulsions stabilized by copolymer B than for those obtained in the presence of copolymer A. A further difference concerns the droplet size, relative viscosity, and loss modulus values obtained at a given dispersed phase volume fraction. At constant copolymer concentrations, it appeared that copolymer B, with a longer PBut sequence, is a more efficient emulsifier and stabilizer than copolymer A. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41390.
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Water-dispersible non-aqueous emulsions stabilized by a poly(butadiene)- b -poly(2-vinylpyridine) block copolymer
Comptes Rendus Chimie, 2014Co-Authors: Leonard Ionut Atanase, Gerard RiessAbstract:Abstract Submicron non-aqueous emulsions, of interest for biomedical and cosmetic formulations, were developed for the system comprising poly(ethylene glycol) (PEG) 400 and Miglyol 812, an enzymatic degradable liquid glycerine ester. These emulsions, with PEG 400 as continuous phase and Miglyol 812 droplets, in the size range of 200 nm, were stabilized by a poly(butadiene)-b-poly(2-vinylpyridine) (PBut-b-P2VP) block copolymer with a composition close to 50/50 wt%. The droplet size, stability and the rheological characteristics were examined as a function of the copolymer concentration. An original aspect of these anhydrous emulsions, with a water miscible continuous phase, is their water dispersibility without additional surfactant. In fact, the initial anhydrous emulsion is sterically stabilized and after water addition at low pH, the protonated P2VP sequence of the copolymer provides the electro-steric stabilization. This oil-in-water emulsion is characterized by sub micron sized Miglyol 812 droplets in an aqueous phase of PEG 400 and water at pH 1.
Jinsong Leng - One of the best experts on this subject based on the ideXlab platform.
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Carboxyl-Terminated Polybutadiene–Poly(styrene-co-4-vinylpyridine) Supramolecular Thermoplastic Elastomers and Their Shape Memory Behavior
Macromolecules, 2016Co-Authors: Chongwen Huang, Fei Wang, Longnan Huang, R. A. Weiss, Jinsong LengAbstract:Aiming at an easy-processing metallo-supramolecular polymer which possesses the shape memory property and large deformation ability, we designed a simple metal coordination complex: the blends of zinc-neutralized carboxyl-terminated polybutadiene and poly(styrene-co-4-vinylpyridine) (PSVP). The two polymers are tightly bound due to the metal coordination interactions between Zn2+ ions from carboxyl-terminated polybutadiene and the pyridine group of the PSVP. The elastomer had reasonably good mechanical properties and was thermoplastic. Improvements in mechanical properties of the blends were realized in the rheology analysis compared with a blend without the introduction of the zinc salt. Small-angle X-ray scattering characterization showed that the microstructure of the elastomeric blend consisted of microphase-separated glassy nanodomains of principally PSVP, which served as cross-link junctions that were connected with polybutadiene chains. The elastomer exhibited good shape memory properties for large...
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carboxyl terminated polybutadiene poly styrene co 4 vinylpyridine supramolecular thermoplastic elastomers and their shape memory behavior
Macromolecules, 2016Co-Authors: Chongwen Huang, Fei Wang, Longnan Huang, R. A. Weiss, Jinsong LengAbstract:Aiming at an easy-processing metallo-supramolecular polymer which possesses the shape memory property and large deformation ability, we designed a simple metal coordination complex: the blends of zinc-neutralized carboxyl-terminated polybutadiene and poly(styrene-co-4-vinylpyridine) (PSVP). The two polymers are tightly bound due to the metal coordination interactions between Zn2+ ions from carboxyl-terminated polybutadiene and the pyridine group of the PSVP. The elastomer had reasonably good mechanical properties and was thermoplastic. Improvements in mechanical properties of the blends were realized in the rheology analysis compared with a blend without the introduction of the zinc salt. Small-angle X-ray scattering characterization showed that the microstructure of the elastomeric blend consisted of microphase-separated glassy nanodomains of principally PSVP, which served as cross-link junctions that were connected with polybutadiene chains. The elastomer exhibited good shape memory properties for large...
Axel H. E. Müller - One of the best experts on this subject based on the ideXlab platform.
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Living Anionic Polymerization in Continuous Flow: Facilitated Synthesis of High-Molecular Weight Poly(2-vinylpyridine) and Polystyrene
Organic Process Research & Development, 2014Co-Authors: Adrian Natalello, Jan Morsbach, Andreas Friedel, Arda Alkan, Christoph Tonhauser, Axel H. E. Müller, Holger FreyAbstract:We describe the living anionic polymerization of 2-vinylpyridine (2VP) and styrene (S) in continuous flow, comparing two micromixing devices with different mixing principles. The use of a continuous flow setup reduces the experimental effort for living anionic polymerizations significantly, compared to a conventional batch system. By adjusting the ratio of the flow rates of the monomer and initiator solutions a variety of different molecular weights can be rapidly synthesized within several minutes, using one setup. Additionally, a comparison of the influence of the two different mixing devices—an interdigital micromixer (SIMM-V2) leading to laminar mixing and a tangential four-way jet mixing device leading to a turbulent mixing pattern—has been achieved. Both setups allow living anionic polymerization in polar solvents at room temperature with full monomer conversion within seconds and yield polymers with narrowly distributed molecular weights. A maximum Mn of approximately 149,000 g mol–1 (PS-9, PDI = 1...
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multiple morphologies phase transitions and cross linking of crew cut aggregates of polybutadiene block poly 2 vinylpyridine diblock copolymers
Macromolecules, 2008Co-Authors: Andreas Walther, Anja S Goldmann, Ram Sai Yelamanchili, Markus Drechsler, Holger Schmalz, Adi Eisenberg, Axel H. E. MüllerAbstract:We describe detailed investigations on the self-assembly of polybutadiene-block-poly(2-vinylpyridine) diblock copolymers into so-called crew-cut micellar aggregates in aqueous media. Three analogous diblock copolymers with different short segments of poly(2-vinylpyridine) were synthesized via anionic polymerization. The self-assembled aggregates are studied in dioxane/water mixtures by means of dynamic light scattering and transmission electron microscopy. Depending on the added volume fraction of water, spherical micelles, branched cylindrical micelles, and vesicles can be found. These aggregates can be cross-linked in a facile fashion using a UV photoinitiator. The structures of the crew-cut aggregates remain intact during cross-linking, yielding stabilized polymeric nanoparticles. A transfer of these nanoparticles into common, only slightly selective solvents, in which no aggregates or different type of aggregates would exist without cross-linking, is possible. The cross-linked nanoparticle structures ...
Leonard Ionut Atanase - One of the best experts on this subject based on the ideXlab platform.
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Water dispersibility of non-aqueous emulsions stabilized and viscosified by a poly(butadiene)-poly(2-vinylpyridine)-poly(ethylene oxide) (PBut-P2VP-PEO) triblock copolymer
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2015Co-Authors: Leonard Ionut Atanase, Jean-philippe Lerch, Gerard RiessAbstract:Abstract Biocompatible non-aqueous emulsions, stabilized by a well-defined poly(butadiene)-poly(2-vinylpyridine)-poly(ethylene oxide) (PBut-P2VP-PEO) triblock copolymer, were developed for the system glycerine ester (Miglyol 812) dispersed in polyethylene glycol (PEG 400). One of the most attractive features of this copolymer is its capacity to form, by hydrogen bonding, thermoreversible micellar systems in PEG 400 with a thermal transition around 43 °C. Moreover, this transition was also observed in the case of a non-aqueous viscosified emulsion, with 30 vol% Miglyol 812 as dispersed phase. An original aspect of this type of emulsions, with a water-miscible PEG 400 continuous phase, is its water dispersibility at pH 1 and pH 7 without any additional surfactant. In fact, the initial non-aqueous emulsion is sterically stabilized and after water addition at pH 1 the copolymer provides a combination of steric and electro-steric stabilization due to the presence of the PEO sequences and of the protonated P2VP units. At pH 7, the stabilization is predominately achieved by the PEO and, to a lesser extent, by the collapsed P2VP sequences. The electro-steric stabilization at pH 1 is more efficient than the steric stabilization at pH 7.
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Stabilization of non-aqueous emulsions by poly(2-vinylpyridine)-b-poly(butadiene) block copolymers
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2014Co-Authors: Leonard Ionut Atanase, Gerard RiessAbstract:Abstract Non-aqueous sub-micron biocompatible emulsions, which are of interest for biomedical and cosmetic formulations, were developed for the system polyethylene glycol (PEG 400) dispersed in a typical liquid glycerine ester (Miglyol 812). These emulsions were stabilized by poly(2-vinylpyridine)- b -poly(butadiene) (P2VP- b -PBut) copolymers, each of these sequences being well adapted to the solubility parameters of the two liquid phases. A comparative study of the emulsifying and stabilization efficiency was performed for two copolymers with quasi-identical molecular weights but of different compositions, such as P2VP 50 - b -PBut 128 ( A ) and P2VP 37 - b -PBut 189 ( B ). These block copolymers form in Miglyol 812 star-like micelles having a P2VP core and a PBut corona. The PEG 400/Miglyol 812 emulsion characteristics were determined as a function of the dispersed phase volume fractions and of the copolymer concentrations. At constant concentrations, copolymer B , with longer Miglyol 812 soluble PBut chains, appeared to be more efficient as emulsifier and stabilizer than copolymer A . By combination of the two block copolymer, a synergetic emulsifying and stabilizing effect could be achieved.
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PEG 400/Paraffin oil non‐aqueous emulsions stabilized by PBut‐Block‐P2VP block copolymers
Journal of Applied Polymer Science, 2014Co-Authors: Leonard Ionut Atanase, Gerard RiessAbstract:For the preparation of PEG 400 in paraffin oil non-aqueous biocompatible emulsions, the stabilization efficiency was compared for two well-defined poly(butadiene)-block-poly(2-vinylpyridine) (PBut-block-P2VP) block copolymers, with similar molecular weights but different compositions. The PBut128-block-P2VP50 and PBut189-block-P2VP37 samples, designated as copolymer A and B, respectively, are self-organized in paraffin oil as micelles with a P2VP core and a PBut corona. The PEG 400/paraffin oil emulsion characteristics were determined as a function of the copolymers concentrations and phase ratios. Higher static and shear stabilities were obtained for emulsions stabilized by copolymer B than for those obtained in the presence of copolymer A. A further difference concerns the droplet size, relative viscosity, and loss modulus values obtained at a given dispersed phase volume fraction. At constant copolymer concentrations, it appeared that copolymer B, with a longer PBut sequence, is a more efficient emulsifier and stabilizer than copolymer A. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41390.
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Water-dispersible non-aqueous emulsions stabilized by a poly(butadiene)- b -poly(2-vinylpyridine) block copolymer
Comptes Rendus Chimie, 2014Co-Authors: Leonard Ionut Atanase, Gerard RiessAbstract:Abstract Submicron non-aqueous emulsions, of interest for biomedical and cosmetic formulations, were developed for the system comprising poly(ethylene glycol) (PEG) 400 and Miglyol 812, an enzymatic degradable liquid glycerine ester. These emulsions, with PEG 400 as continuous phase and Miglyol 812 droplets, in the size range of 200 nm, were stabilized by a poly(butadiene)-b-poly(2-vinylpyridine) (PBut-b-P2VP) block copolymer with a composition close to 50/50 wt%. The droplet size, stability and the rheological characteristics were examined as a function of the copolymer concentration. An original aspect of these anhydrous emulsions, with a water miscible continuous phase, is their water dispersibility without additional surfactant. In fact, the initial anhydrous emulsion is sterically stabilized and after water addition at low pH, the protonated P2VP sequence of the copolymer provides the electro-steric stabilization. This oil-in-water emulsion is characterized by sub micron sized Miglyol 812 droplets in an aqueous phase of PEG 400 and water at pH 1.