Improved synthesis and characterization of saturated branched‐chain fatty acid isomers

Abstract

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.

Skeletal isomerisation of oleic acid over ferrierite: Influence of acid site number, accessibility and strength on activity and selectivity

“…The BUFA obtained by H-Fer-catalysed alkyl isomerisation are a mixture of at least 30 alkyl isomers, predominantly methyl-branched ones [19]. Mono-branched fatty acids (MoBUFA) dominate the reaction mixture with the methyl group being found preferentially at positions 8-14 [19]. Ethyl-branching and propyl-branching are not reported, which is in contrast to fatty acid isomerisation reactions performed with larger pore zeolites [21].…”

“…As in butene isomerisation, the unique topology of ferrierite is believed to be responsible for the transition-state selectivity observed. Further improvements in BUFA production were made by the use of the bulky Lewis base triphenylphosphine (TPP), which has been shown to enhance selectivity by binding to the external acid sites and suppressing residual oligomerisation at the zeolite surface [19]. The selectivity that ferrierite displays in this reaction is remarkable, given the fact that the zeolite shows severe deactivation already after very short reaction times.…”

“…The BUFA obtained by H-Fer-catalysed alkyl isomerisation are a mixture of at least 30 alkyl isomers, predominantly methyl-branched ones [19]. Mono-branched fatty acids (MoBUFA) dominate the reaction mixture with the methyl group being found preferentially at positions 8-14 [19].…”

Tribological Properties of Limonene Bisphosphonates

“…The product contained some acidic di-n-butyl phosphate, which was either present in the original di-n-butyl phosphite or was formed during the synthesis by the oxidation of the di-n-butyl phosphite with the peroxide initiator. The product was dissolved in a mixture of 40 (11)(12)(13)(14)(15)(16)(17)(18)(19), 151 (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19), 137 , 135 (11)(12)(13)(14)(15)(16)(17)(18) …”

“…Other areas being aggressively explored for the development of new biobased base oils and additives with improved properties include the modification of the structures of vegetable oils and their derivatives (fatty acids, fatty esters, etc.) by chemical [13][14][15], thermal [16,17], and enzymatic [18] methods.…”