Kenneth M. Doll

Ester hydroxy derivatives of methyl oleate : Tribological, oxidation and low temperature properties

Five branched oleochemicals were prepared from commercially available methyl oleate and common organic acids; and their lubricant properties were determined. These branched oleochemicals are characterized as 9(10)-hydroxy-10(9)-ester derivatives of methyl oleate. These derivatives show improved low temperature properties, over olefinic oleochemicals, as determined by pour point and cloud point measurements. The derivatization also increased thermo-oxidative stability, measured using both pressurized differential scanning calorimetry (PDSC) and thin film micro oxidation (TFMO) methods. Branched oleochemicals were used as additives both in soybean oil and in polyalphaolefin. Their lubrication enhancement was evaluated by both four-ball and ball-on-disk wear determinations. These derivatives have good anti-wear and friction-reducing properties at relatively low concentrations, under all test loads. Their surface tensions were also determined and a trend was observed. The materials with larger side chain branches had lower surface tension than those containing smaller side chain branches. An exception to this trend was found when studying the compound with the carbonyl containing levulinic acid side chain, which had the highest surface tension of the branched oleochemicals studied. Overall, the data indicate that some of these derivatives have significant potential as a lubricating oil or fuel additives.

The improved synthesis of carbonated soybean oil using supercritical carbon dioxide at a reduced reaction time

We have demonstrated an improved synthesis of a cyclic carbonate of soybean oil (CSO) utilizing supercritical carbon dioxide (CO2) as the solvent. Because the mutual solubility of supercritical CO2 and soybean oil is significantly higher than that of gaseous CO2 and soybean oil, our method synthesizes the material in ∼1/3 of the reaction time reported in the literature. We have also demonstrated a catalyst removal method for our system based on the simple Hofmann elimination reaction, reducing the need for organic solvent extraction. CSO is a potential petroleum replacement, and may be useful in the synthesis of polymers based on bio-resources.

Boron trifluoride catalyzed ring-opening polymerization of epoxidized soybean oil in liquid carbon dioxide

Ring-opening polymerization of epoxidized soybean oil (ESO) catalyzed by boron trifluoride diethyl etherate (BF3·OEt2), in liquid carbon dioxide, was conducted in an effort to develop useful biobased biodegradable polymers. The resulting polymers (RPESO) were characterized by FTIR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), 1H NMR, 13C NMR, solid state 13C NMR spectroscopies and gel permeation chromatography (GPC). The results indicated that ring-opening polymerization of ESO occurred at mild conditions, such as at room temperature, and a subcritical CO2 pressure of 65.5 bar. The formed RPESO materials were highly crosslinked polymers. The glass transition temperatures of these polymers ranged from −11.9 °C to −24.1 °C. TGA results showed that the RPESO polymers were thermally stable at temperatures lower than 200 °C and significant decomposition mainly occurred above 340 °C.

ADSORPTION BEHAVIOR OF EPOXIDIZED FATTY ESTERS VIA BOUNDARY LUBRICATION COEFFICIENT OF FRICTION MEASUREMENTS

The frictional behaviors of a variety of fatty alkenyl esters and their corresponding fatty epoxide esters (epoxy methyl oleate (EMO) and methyl oleate (MO), epoxy methyl linoleate (EMLO) and methyl linoleate (MLO), epoxy methyl linolenate (EMLEN) and methyl linolenate (MLEN)), epoxidized soybean oil (ESBO), and a commercial epoxidized 2-ethylhexyl transesterified soybean oil (VF) as additives in hexadecane have been examined in a boundary lubrication test regime using steel contacts. Langmuir critical additive concentrations were determined, which provide the following order of negative adsorption energies: ESBO > VF > EMO ≥ EMLO > EMLEN and MLEN ≥ MLO > MO. Thus, for the similar epoxidized materials the greater degree of epoxidation results in less negative calculated total adsorption energies; this trend is reversed for the olefinic parent systems. This ordering agrees with that obtained via a more complex unconstrained cooperative interaction adsorption model. Fits of the steady-state coefficient of friction (COF) versus concentration data indicate an inverse relation of the obtained interaction parameters (α) with the primary adsorption energies (E). These results demonstrate the complexity of the adsorption mechanism that occurs.

Synthesis of an Amine−Oleate Derivative Using an Ionic Liquid Catalyst

A facile (and environmentally friendly) reaction between epoxidized methyl oleate and aniline to produce an oleate-aniline adduct, without the formation of fatty amide, was discovered. This reaction was carried out neat, with a catalytic amount of an ionic liquid. No solvent was used, no byproducts were produced, and the ionic liquid could be recovered and recycled. The reaction products were fully characterized by NMR and GC-MS.

Gear oil formulation designed to meet bio-preferred criteria as well as give high performance

A bio-based gear oil was developed from soybean oil (SBO). The SBO was first thermally polymerised and then mixed with additives and diluents. The effect of pour point depressants, co-base oils, antioxidants and anti-wear additives is reported. Lubricity, viscosity index and oxidation stability of the final formulation of the bio-based gear oil are compared with commercially available gear oils. The final formulation of bio-based gear oil gives test results: viscosity index 165, four-ball wear scar 0.375 mm. These numbers are comparable to or better than the commercially available gear oils tested for comparison. The oxidation onset temperature of the bio-based gear oil, 220°C, is lower than the evaluated commercial products, but still at an acceptable range for gear oil.

Synthesis of cyclic acetals (ketals) from oleochemicals using a solvent free method

The reaction selectivities of acid catalyzed ring opening reactions of epoxidized methyl oleate (methyl 9,10-epoxy stearate; EMO), to form either ketal (acetal) or branched ester products have been studied. We have produced methyl 9-(2-butyl-2-methyl-5-octyl-1,3-dioxolan-4-yl) nonanoate (hexanone methyl stearate acetal, HMSA), an oleochemically based ketal (acetal), in 83% isolated yield; from epoxidized methyl oleate and 2-hexanone. Utilizing our reaction chemistry, we have also been able to demonstrate the relative selectivities, in competitive experiments, by reacting EMO with 2-pentanone and octanoic acid. Finally, by controlling temperature and acid concentration, we were able to control the product distribution of the reaction of EMO with the bi-functional levulinic acid. Either the ketal (acetal), or the branched ester product could be favored. This research may help lead to the formation of new hydrophobic molecules for the synthesis of new surfactants from oleochemicals.

Physical properties study on partially bio-based lubricant blends: thermally modified soybean oil with popular commercial esters

Thermally polymerised soybean oil (SBO) is compared with several other vegetable oils, including ordinary SBO and high-oleic SBO (HO SBO). Acid values (AVs) and kinematic viscosities of the oils were measured over 28 days on oils stored at 85°C. As expected, the AVs and viscosities increased with time and the HO SBO demonstrated similar but smaller effects. The thermally modified oil was not better than ordinary SBO necessitating the need for an optimised blending strategy. Lubricant blends were prepared by mixing thermally modified SBO with a series of compatible ester-based synthetic fluids. These displayed oxidative stabilities, by pressurised differential scanning calorimetry, similar to the bio-based oil. Furthermore, the kinematic viscosity and pour point of the lubricant blend could be accurately controlled by careful tuning of the blend ratio.

Decarboxylation of Fatty Acids with Triruthenium Dodecacarbonyl: Influence of the Compound Structure and Analysis of the Product Mixtures

Recently, the decarboxylation of oleic acid (9(Z)-octadecenoic acid) catalyzed by triruthenium dodecacarbonyl, Ru3(CO)12, to give a mixture of heptadecenes with concomitant formation of other hydrocarbons, heptadecane and C17 alkylbenzenes, was reported. The product mixture, consisting of about 77% heptadecene isomers, 18% heptadecane, and slightly >4% C17 alkylbenzenes, possesses acceptable diesel fuel properties. This reaction is now applied to other fatty acids of varying chain length and degree of saturation as well as double-bond configuration and position. Acids beyond oleic acid included in the present study are lauric (dodecanoic), myristic (tetradecanoic), palmitic (hexadecanoic), stearic (octadecanoic), petroselinic (6(Z)-octadecenoic), elaidic (9(E)-octadecenoic), asclepic (11(Z)-octadecenoic), and linoleic (9(Z),12(Z)-octadecadienoic) acids. Regardless of the chain length and degree of unsaturation, a similar product mixture was obtained in all cases with a mixture of alkenes predominating. Monounsaturated fatty acids, however, afforded the alkane with one carbon less than the parent fatty acid as the most prominent component in the mixture. Alkylbenzenes with one carbon atom less than the parent fatty acid were also present in all product mixtures. The number of isomeric alkenes and alkylbenzenes depends on the number of carbons in the chain of the parent fatty acid. With linoleic acid as the starting material, the amount of alkane was reduced significantly with alkenes and alkylaromatics enhanced compared to the monounsaturated fatty acids. Two alkenes, 9(E)-tetradecene and 1-hexadecene, were also studied as starting materials. A similar product mixture was observed but with comparatively minor amount of alkane formed and alkene isomers dominating at almost 90%. The double-bond position and configuration in the starting material do not influence the pattern of alkene isomers in the product mixture. The results underscore the multifunctionality of the Ru3(CO)12 catalyst, which promotes a reaction sequence including decarboxylation, isomerization, desaturation, hydrogenation, and cyclization (aromatization) to give a mixture of hydrocarbons simulating petrodiesel fuels. A reaction pathway is proposed to explain the existence of these products, in which alkenes are dehydrogenated to alkadienes and then, under cyclization, to the observed alkylaromatics. The liberated hydrogen can then saturate alkenes to the corresponding alkane.

Increased functionality of methyl oleate using alkene metathesis

A series of alkene cross-metathesis reactions were performed using a homogeneous ruthenium-based catalyst. Using this technology, a variety of functional groups can be incorporated into the bio-based starting material, methyl oleate. Trans-stilbene, styrene, methyl cinnamate and hexen-3-ol have all been shown to give desirable products. Using this technology, aromatics, alcohols or additional esters can be incorporated into the products. For example, the cross-metathesis reaction of methyl oleate with methyl cinnamate by the second-generation Grubbs catalyst showed 70% conversion of methyl oleate into products where half of the observed products contain an aromatic group and over one-third of the products contain an α,β-unsaturated methyl ester. This promising green route is versatile, and with an appropriate selection of starting materials, it is applicable to the synthesis of polymer precursors, industrial fluids or any other application where the upgrade of natural oils is necessary.