Steven C. Cermak

Improved oxidative stability of estolide esters

Abstract Some concerns have been raised regarding the oxidative stability of vegetable-based fluids. Thus, a wide range of commercial and vegetable-based materials were evaluated for their oxidative stability by the rotating bomb oxidative test (RBOT). RBOT values ranged from 13 to 552 min. Two estolides, coconut-oleic estolide 2-ethylhexyl ester (coco) and oleic estolide 2-ethylhexyl ester (oleic), were evaluated for their oxidative stability by RBOT. As in the case with all vegetable oils, an oxidative stability package must be utilized to help decrease their rate of oxidation. A series of formulations were conducted in which the two estolides had an oxidative stability package added prior to the RBOT. In both cases, dramatic increases in the oxidative stability were observed. The coconut-oleic estolide 2-ethylhexyl ester gave the best RBOT values, 504 min with 3.5% oxidative stability package. Both estolides were formulated to meet commercial crankcase requirements (∼200 min) with as little as 1.0 and 1.5% oxidative stability package. The viscosity index ranged from 179 to 190 for the oleic estolide 2-ethylhexyl ester, whereas the coconut-oleic estolide 2-ethylhexyl ester had slightly lower viscosity indices ranging from 161 to 174. These two estolide esters have displayed far superior oxidative stability, 504 (coco) and 426 (oleic) min, are of reasonable cost, and were more suitable as a base stock for biodegradable lubricants and functional fluids than current commercial, vegetable-based materials.

Biodiesel from meadowfoam (Limnanthes alba L.) seed oil: oxidative stability and unusual fatty acid composition

Meadowfoam (Limnanthes alba L.) seed oil methyl esters (MFME), prepared by a standard transesterification procedure using methanol and sodium methoxide catalyst from refined meadowfoam oil (MFO), were evaluated as a potential biodiesel fuel. MFME contains the unusual 5(Z)-eicosenoate (64.2 wt%) and 5(Z),13(Z)-docosadienoate (18.9 wt%). The cetane number of MFME, 66.9, is among the highest ever reported for a biodiesel fuel. In addition, MFME exhibited exceptionally high oxidative stability of 41.5 h by the Rancimat method. Kinematic viscosity was determined as 6.18 mm2 s−1. The cloud, cold filter plugging and pour points of MFME were determined as −6, −9, and −10 °C, respectively. Blending MFME with soybean oil methyl esters (SME) provided kinematic viscosity and oxidative stability values within ranges specified in ASTM D6751 and EN 14214. Other properties such as acid value, free and total glycerol content, as well as sulfur and phosphorus contents were below limits specified in ASTM D6751 and EN 14214. Also reported are lubricity, heat of combustion, and Gardner color. For sake of comparison of some fuel properties, MFME was also prepared from crude meadowfoam oil. The most conspicuous difference in fuel properties was the even greater oxidative stability of 71.6 h by the Rancimat method of MFME from crude MFO. Addition of MFME (from refined MFO) to petrodiesel improved lubricity of ultra-low sulfur petrodiesel while not adversely affecting oxidative stability and low temperature operability. In summary, MFME has unusual fuel properties as a result of its unique fatty acid composition and appears to be a satisfactory blend component for SME and petrodiesel.

Pilot-plant distillation of meadowfoam fatty acids☆

Abstract Crude meadowfoam fatty acids, which are mainly long chain monoenes, Δ-5 C20, were separated using a Myers 15 pilot plant centrifugal molecular distillation unit to give a distillate that was light in color (Gardner Color=1). One of the problems with crude meadowfoam fatty acids is the color (Gardner Color=18). The optimal distillation conditions were explored by varying the rotor temperature, degas temperature, rotor preheat, and flow rate onto the rotor. As the conditions were varied, the distillate was monitored for color, fatty acid composition, and mass split between distillate and residue. At very high rotor temperatures, the color of the distillate and the fatty acid composition deteriorated, but the same split was observed as with a low rotor temperature. All the variable conditions played a vital role in conducting a successful distillation. In most cases, direct correlations existed between temperatures and amounts of different fatty acids. The optimum conditions were determined through the course of numerous trials and used to distill a large quantity (95 l of meadowfoam fatty acid).

Distillation of Natural Fatty Acids and Their Chemical Derivatives

Well over 1,000 different fatty acids are known which are natural components of fats, oils (triacylglycerols), and other related compounds (Gunstone & Norris, 1983). These fatty acids can have different alkyl chain lengths (typically ten or more carbon atoms), 0-6 carbon-carbon double bonds posessing

Examining Cuphea as a Potential Host for Western Corn Rootworm (Coleoptera: Chrysomelidae): Larval Development

Abstract In previous crop rotation research, adult emergence traps placed in plots planted to Cuphea PSR-23 (a selected cross of Cuphea viscosissma Jacq. and Cuphea lanceolata Ait.) caught high numbers of adult western corn rootworms, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), suggesting that larvae may have completed development on this broadleaf plant. Because of this observation, a series of greenhouse and field experiments were conducted to test the hypothesis that Cuphea could serve as a host for larval development. Greenhouse-grown plants infested with neonates of a colonized nondiapausing strain of the beetle showed no survival of larvae on Cuphea, although larvae did survive on the positive control (corn, Zea mays L.) and negative control [sorghum, Sorghum bicolor (L.) Moench] plants. Soil samples collected 20 June, 7 July, and 29 July 2005 from field plots planted to Cuphea did not contain rootworm larvae compared with means of 1.28, 0.22, and 0.00 rootworms kg−1 soil, respectively, for samples collected from plots planted to corn. Emergence traps captured a peak of eight beetles trap−1 day−1 from corn plots on 8 July compared with a peak of 0.5 beetle trap−1 day−1 on 4 August from Cuphea plots. Even though a few adult beetles were again captured in the emergence traps placed in the Cuphea plots, it is not thought to be the result of successful larval development on Cuphea roots. All the direct evidence reported here supports the conventional belief that rootworm larvae do not survive on broadleaf plants, including Cuphea.

CHAPTER 4:Thiol-ene and H-Phosphonate-ene Reactions for Lipid Modification

This chapter is a short introduction to the thiol-ene reaction and includes the thiol-ene reaction as a click chemistry reaction, radical chain reactions, basic mechanisms and kinetics, the use of the thiol-ene reaction for the synthesis of novel bio-based materials (polymers, lubricants and coatings), addition of H-phosphonates to double bonds, some reaction information and bio-based products, and possible applications of the products (lubricants, plasticizers and anti-microbial agents).

Better than DEET Repellent Compounds Derived from Coconut Oil

Hematophagous arthropods are capable of transmitting human and animal pathogens worldwide. Vector-borne diseases account for 17% of all infectious diseases resulting in 700,000 human deaths annually. Repellents are a primary tool for reducing the impact of biting arthropods on humans and animals. N,N-Diethyl-meta-toluamide (DEET), the most effective and long-lasting repellent currently available commercially, has long been considered the gold standard in insect repellents, but with reported human health issues, particularly for infants and pregnant women. In the present study, we report fatty acids derived from coconut oil which are novel, inexpensive and highly efficacious repellant compounds. These coconut fatty acids are active against a broad array of blood-sucking arthropods including biting flies, ticks, bed bugs and mosquitoes. The medium-chain length fatty acids from C8:0 to C12:0 were found to exhibit the predominant repellent activity. In laboratory bioassays, these fatty acids repelled biting flies and bed bugs for two weeks after application, and ticks for one week. Repellency was stronger and with longer residual activity than that of DEET. In addition, repellency was also found against mosquitoes. An aqueous starch-based formulation containing natural coconut fatty acids was also prepared and shown to protect pastured cattle from biting flies up to 96-hours in the hot summer, which, to our knowledge, is the longest protection provided by a natural repellent product studied to date.

Estolides: Synthesis and Applications**Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer.

Abstract Estolides are formed by the formation of a carbocation at the site of unsaturation that can undergo nucleophilic addition by another fatty acid, with or without carbocation migration along the length of the chain, to form an ester linkage. The secondary ester linkages of the estolide are more resistant to hydrolysis than those of triglycerides, and the unique structure of the estolide results in materials that have far superior physical properties for lubricant applications than traditional vegetable and mineral oils. These benefits, among others, have led formulators to begin using estolides in a variety of industrial and automotive lubricant applications. Combined efforts of the USDA and Biosynthetic Technologies LLC have led to the first estolide motor oil formulations (5W-20 and 5W-30) certified by the American Petroleum Institute (API), which meet the industry’s current motor oil standard. The different types of estolide types and synthesis are described as well as an in-depth look at the physical properties and how they relate to the estolide structures. The current commercial estolide will have some of its properties revealed as well as some information on a Las Vegas, Nevada field trial using estolide-based formulations. Many industry experts consider estolides to be the next generation of high-performance synthetic lubricants.

Estolides: Synthesis and Applications

Abstract Estolides are formed by the formation of a carbocation at the site of unsaturation that can undergo nucleophilic addition by another fatty acid, with or without carbocation migration along the length of the chain, to form an ester linkage. The secondary ester linkages of the estolide are more resistant to hydrolysis than those of triglycerides, and the unique structure of the estolide results in materials that have far superior physical properties for lubricant applications than traditional vegetable and mineral oils. These benefits, among others, have led formulators to begin using estolides in a variety of industrial and automotive lubricant applications. Combined efforts of the USDA and Biosynthetic Technologies LLC have led to the first estolide motor oil formulations (5W-20 and 5W-30) certified by the American Petroleum Institute (API), which meet the industry’s current motor oil standard. The different types of estolide types and synthesis are described as well as an in-depth look at the physical properties and how they relate to the estolide structures. The current commercial estolide will have some of its properties revealed as well as some information on a Las Vegas, Nevada field trial using estolide-based formulations. Many industry experts consider estolides to be the next generation of high-performance synthetic lubricants.

Chapter 14 – Estolides: Synthesis and Applications*

Abstract Estolides are formed by the formation of a carbocation at the site of unsaturation that can undergo nucleophilic addition by another fatty acid, with or without carbocation migration along the length of the chain, to form an ester linkage. The secondary ester linkages of the estolide are more resistant to hydrolysis than those of triglycerides, and the unique structure of the estolide results in materials that have far superior physical properties for lubricant applications than traditional vegetable and mineral oils. These benefits, among others, have led formulators to begin using estolides in a variety of industrial and automotive lubricant applications. Combined efforts of the USDA and Biosynthetic Technologies LLC have led to the first estolide motor oil formulations (5W-20 and 5W-30) certified by the American Petroleum Institute (API), which meet the industry’s current motor oil standard. The different types of estolide types and synthesis are described as well as an in-depth look at the physical properties and how they relate to the estolide structures. The current commercial estolide will have some of its properties revealed as well as some information on a Las Vegas, Nevada field trial using estolide-based formulations. Many industry experts consider estolides to be the next generation of high-performance synthetic lubricants.