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Acid Functionality (acid + functionality)
Selected AbstractsChemInform Abstract: A Facile Synthesis of 5(6)-(Chloromethyl)benzimidazoles: Replacement of a Sulfonic Acid Functionality by Chlorine.CHEMINFORM, Issue 29 2008Bela Pete Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Sorption properties of the iminodiacetate ion exchange resin, amberlite IRC-718, toward divalent metal ionsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008Charef Noureddine Abstract The sorption properties of the commercially available cationic exchange resin, Amberlite IRC-718, that has the iminodiacetic acid functionality, toward the divalent metal-ions, Fe2+, Cu2+, Zn2+, and Ni2+ were investigated by a batch equilibration technique at 25°C as a function of contact time, metal ion concentration, mass of resin used, and pH. Results of the study revealed that the resin exhibited higher capacities and a more pronounced adsorption toward Fe2+ and that the metal-ion uptake follows the order: Fe2+ > Cu2+> Zn2+ >Ni2+. The adsorption and binding capacity of the resin toward the various metal ions investigated are discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Synthesis of Poly(ester-anhydrides) Based on Different Polyester PrecursorsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 7 2004Harri Korhonen Abstract Summary: Poly(ester-anhydrides) were synthesised from poly(L -lactide), poly(D,L -lactide), and poly(, -caprolactone) prepolymers prepared by ring-opening polymerisation of cyclic esters in the presence of 1,4-butanediol or ricinoleic acid as co-initiator. The hydroxyl group end functionality of the prepolymers was converted to carboxylic acid functionality by reaction with succinic anhydride, and the polyester precursors were coupled by melt polycondensation to give poly(ester-anhydrides). 1,4-Butanediol was used as co-initiator to study the properties of poly(ester-anhydrides) prepared from different monomers, whereas ricinoleic acid was used as co-initiator to introduce a hydrophobic fatty acid moiety to the polyester precursor. In hydrolysis tests, the poly(ester-anhydrides) showed a two-stage degradation comprising a rapid hydrolysis of anhydride linkages within three days, followed by the slower hydrolysis of the remaining polyester oligomer. Weight loss of the poly(ester-anhydrides) depended most importantly on molecular weight and thermal properties of the polyester precursors; thus, poly(ester-anhydrides) prepared from low molecular weight prepolymers having thermal transitions below 37,°C showed very fast weight loss. [source] Stimuli-responsive properties of aminophenylboronic acid-carrying thermosensitive copolymersPOLYMER INTERNATIONAL, Issue 5 2003Abstract Thermosensitive copolymers of N -isopropylacrylamide (NIPA) and N -acryloxysuccinimide (NASI) were obtained by solution polymerization using azobisisobutyronitrile as the initiator in a tetrahydrofuran,toluene mixture at 65,°C. A boronic acid-carrying ligand, m -aminophenylboronic acid (APBA) was covalently attached to the thermosensitive copolymer via the reaction between amino and succinimide groups. APBA-coupled thermosensitive copolymer exhibited both temperature and pH sensitivity. Thermally reversible phase transitions were observed both in the acidic and alkaline pH region for the APBA-modified copolymers obtained with different NASI feed concentrations. In our study, ribonucleic acid (RNA) was selected as a biomolecule having reactive groups which could potentially interact with the boronic acid functionality. The response of boronic acid-carrying thermosensitive copolymer against RNA was investigated in aqueous media in the pH range 4,9. In the acidic pH region, an increase was observed in the lower critical solution temperature (LCST) of the APBA-coupled thermosensitive copolymer with increasing RNA concentration. However, LCST decreased with increasing RNA concentration at both neutral and alkaline pH values. The LCST of the APBA-attached copolymer varied linearly with the RNA concentration at pH of 3, 4 and 7. © 2003 Society of Chemical Industry [source] Innovative membrane based process for the selective oxidation of light alkanes assisted by the Fenton systemASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2010C. Espro Abstract Selective oxidation of light alkanes under mild conditions (temp, 80,120 °C; pressure, 140 kPa) mediated by Fe2+/H2O2 Fenton system on Nafion based composite membranes is studied in a multifunctional three phase catalytic membrane reactor (3PCMR). The role of textural properties and acid functionality on the catalytic performance of the Nafion composite membranes is outlined. The features of the multifunctional 3PCMR, enabling reaction along with product separation and recovery, are discussed. 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