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The specific ionic conductivity, dynamic viscosity, and electrochemical stability of several imidazolium salts are reported as neationic liquids and their solutions in several organic solvents. The temperature dependence of conductivity and viscosity are analyzed for 1‐ethyl‐3‐methylimidazolium false(EMI+false) and 1,2‐dimethyl‐3‐n‐propylimidazolium false(DMPI+false) salts, and the influence of theanions bis(trifluoromethylsulfonyl)imide false(Im−false) , bis(perfluoroethylsulfonyl)imide false(Beti−false) , hexafluoroarsenate false(AsF6−false) , hexafluorophosphate false(PF6−false) , and tetrafluoroborate false(BF4−false) on these properties are discussed. These imidazolium salts make possible electrolytes with high concentration (>3 M), high room temperature conductivity (up to 60 mS/cm), and a wide window of stability false(>4Vnormalat 20 μA/cm2false) . Differential scanning calorimetric results confirm a large glass phase for the ionic liquids, with substantial (>80°C) supercooling. Thermal gravimetric results indicate the imidazolium salts with Im− and Beti− anions to be thermally more stable than the lithium salt analogs. The Vogel‐Tammann‐Fulcher interpretation accurately describes the conductivity temperature dependence. © 1999 The Electrochemical Society. All rights reserved.

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The development of viable technologies for producing green products from renewable fats and oils is highly desirable since such materials can serve as replacements for non‐renewable and poorly biodegradable petroleum‐based products. Mixtures of saturated branched‐chain fatty acid isomers (sbc‐FAs), commonly referred to as isostearic acid, are important intermediates for the production of biodegradable lubricants, cosmetics, emollients, and hydraulic fluids. Present methods for producing sbc‐FAs, however, often give low yields of sbc‐FAs or sbc‐FA preparations with a high content of dimer acid fatty acid co‐products. This study reports an improved route to synthesizing sbc‐FAs from monounsaturated fatty acids using a modified H‐Ferrierite zeolite catalyst in conjunction with small amounts of triphenylphosphine additive. The yields of sbc‐FAs (up to 80 wt%) and co‐products (up to15 wt%) were determined using a modification of a previously reported GC method. A more detailed analysis of the distribution of sbc‐FA isomers in the products was made by the combined use of GC × GC‐TOF‐MS. Additionally, it was found that the H‐Ferrierite zeolite catalyst was recyclable and reusable up to 10 times without significant loss of activity and selectivity for sbc‐FAs.

Zeolite-catalyzed isomerization of oleic acid to branched-chain isomers*Branched-chain (bc) saturated fatty acids (SFA) have potential as oleochemical intermediates since they have better oxidative stability than linear unsaturated fatty acids (UFA) and have better low-temperature properties than linear SFA. Previous studies in converting UFA to bc-FA using clay catalysts have resulted in only modest yields and conversions. Recent reports, however, have suggested that certain zeolites can be effective catalysts for converting UFA to bc-FA in higher yields and conversions. In this work, we examined the scope and potential of the zeolite-catalyzed synthesis of bc-FA starting from readily available monounsaturated linear FA. Our results show that common UFA such as oleic acid can be converted to bc-isomers using modified Ferrierite zeolite catalysts with high conversions (98%) and high selectivity (85%) and that the zeolite catalysts are reusable for at least three cycles. The positions of branching (methyl) on the FA chain were determined from the GC-MS spectra of the picolinyl esters of the bc-FA.