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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Bio-oils Research » Research » Publications at this Location » Publication #312951

Title: Synthesis and physical properties of new coco-oleic estolide branched esters

item Cermak, Steven - Steve
item BREDSGUARD, JAKOB - Biosynthetic Technologies
item ROTH, KATIE - Biosynthetic Technologies
item THOMPSON, TRAVIS - Biosynthetic Technologies
item FEKEN, KATI - Biosynthetic Technologies
item Isbell, Terry
item Murray, Rex

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2015
Publication Date: 5/25/2015
Publication URL:
Citation: Cermak, S.C., Bredsguard, J.W., Roth, K.L., Thompson, T., Feken, K.A., Isbell, T.A., Murray, R.E. 2015. Synthesis and physical properties of new coco-oleic estolide branched esters. Industrial Crops and Products. 74:171-177.

Interpretive Summary: Vegetable oil based oils usually fail to meet the rigorous demands of industrial lubricants by not having acceptable low temperature properties. Estolides are made through the use of a material from various sources of vegetable oil. Estolides are unique in that they can be custom-designed to perform under different conditions rather than trying to formulate an unacceptable material into a more acceptable one which is a common practice in the petroleum industry. A series of new compounds, coco-oleic estolides esters, were developed to help maximize low temperature and viscosity properties of the oil. Finally, having a green biobased industrial fluid that has good cold weather properties would be highly desirable. These new coco-oleic estolide esters required no additives in order to obtain the improved low temperature performance, thus limiting our impact on the environment and helping reduce our dependence on foreign oil imports.

Technical Abstract: Oils derived from vegetable oils tend to not meet the standards for industrial lubricants because of unacceptable low temperature properties, pour point (PP), and/or cloud point (CP). However, a catalytic amount of perchloric acid with oleic and coconut (coco) fatty acids produced a coco-oleic estolide. The resulting coco-oleic estolide was separated into two components based on the extent of oligomerization: coco-oleic dimer estolide and coco-oleic trimer plus estolide. These two estolides were then esterified with a series of different branched alcohols. The coco-oleic dimer estolide esters had the lowest PP = -45 deg C when with esterified 2-hexyldecanol and PP = -39 deg C with 2-octyldodecanol. The best CP performer from the same series was the 2-octyldodecanol ester, CP = -37. The coco-oleic trimer plus estolide esters had slightly higher PPs (-24 to -39 deg C) with the same alcohols. The viscosities and viscosity indexes were as expected in terms of trends. The coco-oleic dimer estolide esters ranged 27.5-51.7 cSt @ 40 deg C and 3.0-9.5 cSt @ 100 deg C, whereas the coco-oleic trimer plus estolide esters ranged 120.8-227.7 cSt @ 40 deg oC and 17.9-29.4 cSt @ 100 deg C for the same series as the dimer esters. Outside the series tested, an iso-stearyl trimer plus ester had the highest reported viscosity of 417.3 cSt @ 40 deg C and 38.9 cSt @ 100 deg C. Because these new branched estolide esters have excellent viscosity and low temperature physical properties without the addition of other chemicals, they minimize the effect on the environment while replacing nonrenewable products.