Zengshe Liu

One-pot synthesis of chemically modified vegetable oils.

Vegetable oils are promising candidates as substitutes for petroleum base oils in lubricant applications, such as total loss lubrication, military applications, and outdoor activities. Although vegetable oils have some advantages, they also have poor oxidation and low temperature stability. One of the ways to address these issues is chemical modification of fatty acid chain of triglyceride. We report a one-pot synthesis of a novel class of chemically modified vegetable oils from epoxidized triacylglycerols and various anhydrides. In an anhydrous solvent, boron trifluoride etherate is used as catalyst to simultaneously open the oxirane ring and activate the anhydride. The reaction was monitored and products confirmed by NMR, FTIR, GPC, and TGA analysis. Experimental conditions were optimized for research quantity and laboratory scale-up (up to 4 lbs). The resultant acyl derivatives of vegetable oil, having diester substitution at the sites of unsaturation, have potential in formulation of industrial fluids such as hydraulic fluids, lubricants, and metal working fluids.

Synthesis of Soybean Oil-Based Polymeric Surfactants in Supercritical Carbon Dioxide and Investigation of Their Surface Properties

This paper reports the preparation of polymeric surfactants (HPSO) via a two-step synthetic procedure: polymerization of soybean oil (PSO) in supercritical carbon dioxide followed by hydrolysis of PSO (HPSO) with a base. HPSO was characterized and identified by using a combination of FTIR, (1)H NMR, (13)C NMR, and GPC methods. The effects of HPSO polysoaps on the surface tension of water and interfacial tension of water-hexadecane were investigated as a function of concentration of HPSO and counterion chemistry. HPSO polysoaps were effective at lowering the surface tension of water and the interfacial tension of water-hexadecane. They displayed minimum values of surface tension in the range of 20.5-39.6 dyn/cm at a concentration range of 3.2-32 μM and minimum values of interfacial tension in the range of 15.6-31.44 dyn/cm. The minimum surface and interfacial tension values were highly dependent on the nature of the counterion and increased in the order K(+) < Na(+) < TEA(+). These results suggested that a very low concentration of surfactant can be used to reduce the surface tension of water and interfacial tension of water-hexadecane. Water-hexadecane interfacial energy was also calculated from measured surface tension data using Antonoff, harmonic mean (HM), and geometric mean (GM) methods. Measured values agreed well with those calculated using the HM and GM. The HM method predicted slightly higher values than the GM method, but the Antonoff method did not agree with measured values.

Microwave-assisted synthesis of cyclodextrin polyurethanes

Cyclodextrin (CD) has often been incorporated into polyurethanes in order to facilitate its use in encapsulation or removal of organic species for various applications. In this work a microwave-assisted method has been developed to produce polyurethanes consisting of α-, β-, and γ-CD and three common diisocyanates. As compared to conventional heating, this new synthetic method saves energy, significantly reduces reaction time, and gets similar or improved yield. The reaction products have been fully characterized with (13)C, (1)H, and two-dimensional NMR spectroscopy. With suitable stoichiometry of starting CD and diisocyanate, the resulting CD polyurethane is organic-soluble and water-insoluble and is shown to remove Nile red dye and phenol from water. Possible applications include the removal of undesirable materials from process streams, toxic compounds from the environment, and encapsulation of color or fragrance molecules.

Modified flax fibers reinforced soy-based composites: mechanical properties and water absorption behavior

Flax fibers are often used in reinforced composites which have exhibited numerous advantages such as high mechanical properties, low density and biodegradablility. On the other hand, the hydrophilic nature of flax fiber is a major problem. In this study, we prepare the soybean oil based composites reinforced with protein coated and lipid acylated flax fibers and compare their water uptake properties. Results showed that water resistance properties of the composites are improved where treated flax fibers are used. The composite with lipid acylation of the flax fiber exhibited to enhance tensile strength and water resistance properties. Influences of fiber length, fiber loading and pressure on mechanical properties are also reported.

Polymerization of epoxidized triglycerides with fluorosulfonic acid

ABSTRACT The use of triglycerides as agri-based renewable raw materials for the development of new products is highly desirable in view of uncertain future petroleum prices. A new method of polymerizing epoxidized soybean oil has been devised with the use of fluorosulfonic acid. Depending on the reaction conditions, one can get a viscous oil or a solid as the reaction product. The reaction mechanism has been studied through a systematic examination of the fluorosulfonic acid-initiated reaction of epoxidized methyl oleate and epoxidized methyl linoleate. Through 13C NMR spectroscopy, the major species derived from fluorosulfonic acid-initiated polymerization of epoxidized soybean oil have been determined. The effects of temperature, initiator dosage, and reaction time have been studied and shown to affect the nature of polymer products obtained and the distribution of different chemical species present.

Chemical Modification of Vegetable Oils for Lubricant Basestocks

Use of vegetable oil based lubricants will reduce petroleum imports and have a favorable environmental impact. The vegetable oils are derived from a renewable sources, biodegradable, non-toxic, possess high flash points and have low volatility. Inadequate oxidative stability and poor low-temperature properties of vegetable oils limit their utilization as lubricants. In this study, we report the development of chemical modification methods to improve these functional properties. The resultant vegetable oil derivatives having diester substitution at the sites of unsaturation shows comparable properties to mineral base fluids.© 2003 ASME

Derivatives of Cardanol through the Ene Reaction with Diethyl Azodicarboxylate

Cardanol is an alkyl/alkenyl phenolic material obtained from cashew nut shell liquid (CNSL), which is a byproduct of cashew nut processing. In an effort to develop new uses, cardanol was derivatized for the first time with diethyl azodicarboxylate (DEAD) through the ene reaction. The reaction was facile and required only the application of heat without a catalyst. Both conventional heating and microwave heating were shown to be effective; the latter entailed much shorter reaction time and substantial energy savings. The reaction product (a hydrazino-ester derivative of cardanol) was characterized by nuclear magnetic resonance (NMR). The product increased in viscosity with time and may be useful as a viscosifier in oil-based commercial formulations and as a synthon for further organic reactions.

Synthesis of a cardanol-amine derivative using an ionic liquid catalyst

Cardanol is a biobased raw material derived from cashew nut shell liquid. In order to extend its utility, new derivatives and additional applications are useful. In this work cardanol was first epoxidized, and a novel aniline derivative prepared from it under mild reaction conditions with the help of an ionic liquid catalyst. The reaction chemistry was studied by using nuclear magnetic resonance. The resulting aminohydrin adduct showed antioxidant property and should also be a useful synthon for further reactions. As an example, the aminohydrin was shown to undergo a condensation reaction with formaldehyde to form a prepolymer, which could be further reacted to form thermosetting resins.

CHAPTER 11:The Potential of Vegetable Oils for Lubricants

Vegetable oils offer significant advantages in terms of resource renewability, bio-degradability, and comparable performance properties to petroleum-based products. Petroleum-based lubricants render an unfavorable impact on the environment. With growing environmental concerns, seed oils are finding their way into lubricants for agricultural, marine, forestry and industrial applications. Their amphiphilic character makes them excellent candidates as lubricants. The wide use of vegetable oils is restricted due to their low thermo-oxidative stability and poor cold-flow behavior. This chapter will discuss the screening of various seed oils, genetically modified oils, and chemically modified oils as basestocks for lubricant formulations; and how oxidative stability and cold-flow properties can be improved with the use of chemical additives. Important lubricant properties, such as oxidative stability, low-temperature-flow properties, friction and wear behavior, and viscosities of these oils will also be discussed. Among these oils, the best ones are high-oleic vegetable oils which, when formulated with chemical additives, provide lubricants exhibiting improved low-temperature properties, and superior oxidative stability and wear properties.