2008 Annual Report 1a.Objectives (from AD-416) 1. Investigate the tribological properties of ag-based products of interest in metalworking lubricant formulation. 2. Develop and apply tribological predictive models for ag-based raw materials of interest in metalworking lubricant formulation. 1b.Approach (from AD-416) (1) Bio-based materials of interest in metalworking lubrication will be obtained from various commercial and non-commercial sources. These will include starches, proteins, vegetable oils, modified vegetable oils, and composites (e.g. starch-oil composite FanteskTM). Chemically and/or enzymatically modified materials will be obtained from sources within and outside of ARS. Collaboration will be pursued with industry and academia actively engaged in the development of new bio-based raw materials. Tribological properties will be investigated using a variety of equipment currently available at NCAUR (4-ball EP, 4-ball AW, Timken EP, ball-on-flat, pin-on-disk, ball-on-disk, block-on-ring, EHD). Ex-situ and post-mortem -tribochemical studies will be conducted using instruments currently available at NCAUR. In-situ tribochemical studies will be conducted using instrument(s) to be developed later in the program. Tribosimulation tests will be conducted using Tapping Torque tribosimulator currently at NCAUR. Prototype tests will be conducted at partners' facilities. Formulations that successfully performed in prototype tests will be produced in pilot scale quantity at NCAUR. Commercial blenders will be certified for producing larger quantities for use in production mill trials. (2) Modeling efforts will be focused around metalworking processes of interest to partners. Models that allow for the prediction of interface film thickness and tribochemistry will be developed. These parameters are selected because of their profound effect on critical metalworking outcomes such as: friction, wear, product surface quality, lubricant quality, exposure, safety, pollution, etc. Development of these models requires detailed data on biobased materials, tools, workpiece, and process parameters. Some of this data will be generated in this program while others will be obtained from partners and/or from the literature. Predictive capability of models will be evaluated and fine-tuned through additional experiments in collaboration with CRADA partners. Models will then be implemented and used to help accelerate development of metalworking lubricant formulations for various metalworking applications. 3.Progress Report The effect of blending seed oils with petroleum-based synthetic fluids on a number of critical lubricant properties was investigated. Such investigation is important because, for some lubrication applications, biobased ingredients by themselves are inadequate and must be blended with petroleum based and/or synthetic based fluids to provide acceptable performance. Experiments were conducted to investigate the lubrication properties of biobased ingredients in the mixed film regime. Most lubrication processes, including various metalworking operations, are known to occur in the mixed film regime. Knowledge gained in this work will be critical for the development of biobased metalworking lubricants. A procedure was developed for a one-step chemical reaction to incorporate extreme pressure (EP) functional groups into molecules of seed oils. EP functional groups are incorporated into metalworking lubricant formulations in order to prevent contact between tool and workpiece during lubrication processes that occur at very high loads. Products from this procedure will be further investigated for their tribological properties in biobased lubricant formulations. In collaboration with another project (3620-41000-117-00D), the adsorption properties of heat modified soybean oils were investigated. Heating causes soybean oil to oligomerize, and is used to produce various viscosity grades of soybean oil. It was of interest to determine how changes in molecular weight and structure caused by heat modification affects the adsorption of soybean oil molecules on friction surfaces. Adsorption is a critical property of lubricant ingredients and affects their boundary lubrication properties. This research addresses NP 306, Component 2. 4.Accomplishments 1. Investigation of the tribological properties of blends of biobased and non-biobased base oils. Biobased ingredients by themselves may not possess the required characteristics for some lubrication applications. One solution to this problem is to blend them with petroleum based and/or synthetic based ingredients. In order to ensure the desired outcome from such a blend requires knowledge of and ability to predict the effect of blending variables on blend properties. In this work, binary blends of seed oils and synthetic base fluids were investigated for their film forming, viscosity, pressure-viscosity, and temperature-viscosity properties. This investigation was done at a fixed load as a function of blend component chemical structure, blend composition, temperature, and speed. The experimental results were analyzed using a variety of theoretical models. It was found that these blend properties can be reasonably predicted using existing theoretical models. The potential impact of this accomplishment is that it will allow for the development of predictive capability, for the efficient selection of components for formulating blends with specified properties. This research addresses NP 306, Component 2, Problem Area 2a. 2. Investigation of the tribological properties of biobased lubricants in the mixed-film regime. Metalworking and a number of other lubrication processes occur in the mixed-film regime. Thus, understanding the behavior of farm-based ingredients in this regime is critical to the development of biobased metalworking lubricants. In this work, the friction and wear properties of various biobased ingredients were investigated as a function of lubrication process parameters such as: speed, load, temperature, viscosity, and concentration. Varying the process parameters allowed for investigation of the mixed-film as well as the adjoining lubrication regimes. The results were found to conform with predictions of existing lubrication theory. One potential impact of this accomplishment is that it produced new data that can be used in predictive model development and to accelerate biobased and metalworking lubricant development. This research addresses NP 306, Component 2, Problem Area 2a. 3. Development of functionalized biobased fluids by chemical modification. Biobased metalworking lubricants must meet a number of stringent performance requirements before they can be widely used. One of the most important requirements is the ability to prevent contact between tool and workpiece during lubrication processes that occur at very high loads of extreme pressure (EP). One method that is widely practiced in order to meet such a requirement is to add an EP additive into the metalworking lubricant formulation. Another method is to chemically modify the biobased fluid so that the EP functional group is part of the biobased molecule. The later method is preferred because, among other things, it eliminates the need for: (a) purchasing and inventorying EP additives, and (b) regularly monitoring and adjusting the concentration of additives in the formulation. In this work, a procedure was developed for a one-step chemical reaction to incorporate EP functional groups into the molecules of seed oils. The developed method allows for inserting the EP functional group into 89% of the seed oil molecule reactive sites, and producing 60% isolated yield. The potential impact of this accomplishment is that it will allow for the development of simple (fewer ingredients) but effective EP lubricants for metalworking and other applications. This research addresses NP 306, Component 2, Problem Area 2a. 5.Significant Activities that Support Special Target Populations None. 6.Technology Transfer Number of Active CRADAs 1 Number of New Commercial Licenses Executed 1 Review Publications Biresaw, G., Shogren, R.L. 2008. Friction properties of chemically modified starch. Journal of Synthetic Lubrication. 25(1):17-30. Biresaw, G., Liu, Z., Erhan, S.Z. 2008. Investigation of the surface properties of polymeric soaps obtained by ring-opening polymerization of epoxidized soybean oil. Journal of Applied Polymer Science. 108(3):1976-1985. Biresaw, G. 2008. Tribological properties of ag-based amphphiles. In: Biresaw, G., Mittal, K.L., editors. Surfactants in Tribology. 1st edition. Boca Raton, FL: Taylor & Francis. p. 259-290.