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Direct Fluorination (direct + fluorination)
Selected AbstractsA Detailed Account of a Convenient Lab-Scale Preparation of AsF5 via Direct Fluorination as AsF3.CHEMINFORM, Issue 1 2006Damian R. Aris Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of Perfluorinated Carboxylic Acid Membrane Monomers by Utilizing Liquid-Phase Direct Fluorination.CHEMINFORM, Issue 40 2005Takashi Okazoe Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of Fluorinated Dimethyl Carbonates by Direct Fluorination.CHEMINFORM, Issue 38 2004Masahiro Takehara Abstract For Abstract see ChemInform Abstract in Full Text. [source] Direct fluorination of Twaron fiber and investigation of mechanical thermal and morphological properties of high density polyethylene and Twaron fiber compositesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008J. Maity Abstract Composites consisting of high density polyethylene (HDPE) reinforced with randomly oriented chopped Twaron fibers (both fluorinated and nonfluorinated) show a significant increase in mechanical and thermal properties. To increase the better fiber matrix adhesion, the Twaron fiber is surface fluorinated using elemental fluorine. The surface of the Twaron fiber becomes very rough and the diameter of Twaron fiber increases from , 12 to 14 ,m after fluorination. The composites were prepared using solution method to overcome the damage of the fiber. The tensile strength and the Young's modulus increases with increasing fiber content. The tensile strength and modulus of modified fiber (fluorinated Twaron fiber) composites is much higher than nonmodified fiber composites indicating that there is better mechanical interlocking between the modified fiber and the matrix. Thermal properties obtained from DSC and DTA-TG analysis of the fluorinated fiber composites are also improved. Contact angle measurements, as well as the surface energy measurements, indicate that the composites are more wettable and is maximum for fluorinated fiber composites i.e., surface energy for fluorinated fiber composites is highest. Crystallinity is also higher for fluorinated fiber composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 [source] Trifluoromethanesulfonic acid, an alternative solvent medium for the direct electrophilic fluorination of DOPA: new syntheses of 6-[18F]fluoro- L -DOPA and 6-[18F]fluoro- D -DOPAJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 14 2007Babak Behnam Azad Abstract Previous work from this laboratory has shown that the direct fluorination of 3, 4-dihydroxy-phenyl- L -alanine (L -DOPA) in anhydrous HF (aHF) or BF3/HF with F2 is an efficient method for the synthesis of 6-fluoro- L -DOPA. Since then, 18F-labeled 6-fluoro- L -DOPA ([18F]6-fluoro- L -DOPA) has been used to study presynaptic dopaminergic function in the human brain and to monitor gastrointestinal carcinoid tumors. This work demonstrates that the reactivity and selectivity of F2 toward L -DOPA in CF3SO3H is comparable with that in aHF. This new synthetic procedure has led to the production of [18F]fluoro- L -DOPA and [18F]fluoro-D-DOPA isomers in 17±2% radiochemical yields (decay corrected with respect to [18F]F2). The 2- and 6-FDOPA isomers were separated by HPLC and subsequently characterized by 19F NMR spectroscopy. The corresponding [18F]-FDOPA enantiomers have been obtained in clinically useful quantities by a synthetic approach that avoids the use of aHF. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||