Scientists Develop New Crankcase Lube From Plants
By Jan Suszkiw
June 15, 2006
Coming to a crankcase near you:
"estolides," the latest biobased lubricant, compliments of
Agricultural Research Service (ARS)
scientists in Peoria, Ill.
Today's biobased lubes owe their famed biodegradability to their
vegetable-oil or animal-fat origins. But many can't match the cold-weather
performance, cost or oxidative stability of petroleum-based formulations.
The estolides are a different storyor such is the indication from
tests carried out by
Isbell and others at the ARS
Center for Agricultural Utilization Research, in Peoria.
There, the team overcame the pitfalls of standard biobased lubes by
chemically connecting different unsaturated fatty acids (FAs). These are the
building blocks of high-oleic oils, such as sunflowers, canola and lesquerella.
Normally, an edible oilfor example, from soybeansis modified to
produce the desired biobased industrial product, such as grease or hydraulic
fluid. The Peoria team used only the FA components, producing branched chains
of either saturated or unsaturated oleic estolides whose performance in
crankcase trials rivaled that of mineral-oil-based lubes, which are
For example, the lowest temperature at which the scientists could pour a
conventional soy-based lube before it thickened into a gel was -0.4 degrees
Fahrenheit, whereas for two commercial mineral-oil formulations, the pour
points were -4 degrees F and -40 degrees F. This compares to -22 degrees F for
the unsaturated oleic estolides and -40 degrees F for the saturated ones.
And in a standard oxidative-resistance test, called RBOT for short, the two
estolide lubes withstood oxidative breakdown for 200 and 400 minutes,
respectively, versus 60 to 80 for standard biobased formulations, and 200 for
mineral oil used in cars.
The researchers' studies on estolides, begun in 2000, dovetail with an ARS
push to develop biobased products that could help diminish U.S. dependence on
In March 2006, ARS and Peaks and Prairies, L.L.C., of Malta, Mont., entered
into a cooperative research and development agreement to explore creating
ARS is the U.S. Department of
Agriculture's chief scientific research agency.