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Showing 1 to 20 of 165 for “"Sulfone"”.
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Switchable butadiene sulfone pretreatment of lignocellulosic biomass
… a new pretreatment method using butadiene sulfone (C4H6O2S), a solvent that is inexpensive and recyclable, and effectively pretreats biomass in one step under mild conditions. The production and recovery of butadiene sulfone is available at an industrial scale, thus facilitating a potential …
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TRANSITION METAL CATALYZED CROSS-COUPLINGS OF ALKYL SULFONE ELECTROPHILES
Sulfones are an important class of organic molecules that can participate in a wide variety of synthetic transformations. For this reason, they have been described as chemical chameleons. While their use as Csp2 electrophiles in cross-coupling dates to the early 1970’s, their potential as competent …
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Synthesis of poly(arylene ether sulfone)-polyimide segmented copolymers
Poly(arylene ether sulfone) oligomers have been synthesized by nucleophilic aromatic substitution using potassium carbonate as base and N-methyl pyrrolidinone (NMP) as solvent. m-Aminophenol was used as an endcapper to control the molecular weight of the oligomers and to provide functional amine …
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Synthese chiraler Sulfone aus Sulfoximinen in Lösung und an fester Phase
Synthesis of chiral sulfones using sulfoximines in solution and on solid phase Abstract: Allylic sulfoximines were synthesised in a one pot reaction starting from (S)-N,S-dimethylphenylsulfoximine in high yields. The following g-hydroxyalkylation with functionalised aldehydes was achieved with …
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Modified Poly(arylene ether sulfone) Compositions and their Segmented Block Copolymers
A series of modified poly(arylene ether sulfone)s (PAES) incorporating hexafluoroisopropylidene units and co-monomers, bisphenol A (BA), 4,4′-dihydroxyterphenyl (DHTP) and triptycene-1,4-hydroquinone (TPDH), were synthesized using a polyetherification synthetic method. These thermoplastic PAES were …
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Benign Processing of High Performance Polymeric Foams of Poly(arylene ether sulfone)
… density reduction) foam from poly(arylene ether sulfone) (PAES). Water and supercritical carbon dioxide (scCO2) were used as the blowing agents in a one-step batch foaming process. Both water and scCO2 plasticize the PAES, allowing for precise control on both the foam morphology and the foam …
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Synthesis and Characterization of Sulfonated Poly(arylene ether sulfone)s for Membrane Separations
Sulfonated poly(arylene ether sulfone)s are a class of engineering thermoplastics well-known for their mechanical properties and chemical/oxidative stability. The research in this dissertation focuses on modifying the structure of sulfonated poly(arylene ether sulfone)s to improve membrane …
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Synthesis and basic characteristics of segmented poly(arylene ether sulfone)-poly(arylate) copolymers
… hydroquinone, biphenol, and dichlorodiphenylsulfone. This reaction was conducted in the presence of potassium carbonate and anhydrous aprotic dipolar solvents. Poly(biphenol terephthalate) and poly(oxybenzoate) were synthesized in situ as the second, potentially anisotropic, sem;crystalline …
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Development of Highly Reactive Sulfone Iminium Fluoride Reagents and Their Application in Fluorine Methodologies
… part of this work, we report the synthesis of sulfone iminium fluorides (SIFs), a new and highly reactive sulfur (VI) fluoride reagent class. A small library of these compounds was synthesized in five simple, modular steps from cheap starting materials. The SIF reagents successfully convert …
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Synthesis and Characterization of Poly(arylene ether sulfone)s with Novel Structures and Architectures
Poly(arylene ether sulfone)s with dendritic terminal groups were synthesized by step-growth polymerization of two difunctional monomers in the presence of preformed dendritic end-cappers. These polymers were characterized by NMR, SEC, DSC, TGA, melt rheology and tensile tests. The melt viscosities …
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Synthesis and Characterization of trans-1,4-Cyclohexylene Ring Containing Poly(arylene ether sulfone)s
Poly(arylene ether sulfone)s (PAES) are important commercial polymers and have been extensively studied due to their excellent thermal and mechanical properties. However, some applications are still limited when good solvent resistance and low thermal expansion coefficient are required. There has …
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Design and development of stimuli-responsive materials: pH sensitive polymersomes and poly(olefin sulfone)s
… base-, heat-, and fluoride-sensitive poly(olefin sulfone)s. Polymersomes are a useful approach for encapsulation but are susceptible to environmental stressors and leakage. By tuning the nanoscale architecture of the polymersomes with reversible chemical modifications, their stability can be …
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Solution-casting of Disulfonated Poly(arylene ether sulfone) Multiblock Copolymer Films for Proton Exchange Membranes
… properties of disulfonated poly(arylene ether sulfone) multiblock copolymer films from the viewpoint of phase separation of block copolymers. Of equal importance to this work, is a possibility of utilizing a rheological technique for monitoring the transformation and kinetics of block …
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Pd-katalysierte asymmetrische Synthese allylischer Sulfone und Stereochemie der Lithiumsalze chiraler allylischer Alpha-tert-Butylsulfonyl-Carbanionen
… leads to chiral allylic tert-Butylallylsulfones in high yields up to 96% and selectivities up to 98%. Deprotonation of said compounds in alpha-position to their sulfonyl-group forms alpha-tert-Butylsulfonylcarbanions, which are characterized by a hindered rotation around the …
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Synthesis and Characterization of New Aryl Phosphine Oxide and Ketone Containing Poly(arylene Sulfide Sulfone)s
High molecular weight poly(phenylene sulfide sulfone) (PPSS) homo- and statistical copolymers have been reproducably synthesized using a known, but complex procedure utilizing 4,4'-dichlorodiphenyl sulfone (DCDPS), sodium hydrosulfide, sodium hydroxide, sodium acetate, and deionized water, in NMP …
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Synthesis and Characterization of Highly Functional Substituted Stilbene Copolymers and Semi-crystalline Poly(aryl ether sulfone)s
… has been incorporated into poly(aryl ether sulfone)s (PAES) in a study to impart crystallization to these amorphous polymers. Three bisphenols, 4, 4′-isopropylidenediphenol, 4, 4′-(hexafluoroisopropylidene)diphenol and 4,4′-dihydroxybiphenyl have been copolymerized with DHTP and …
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