Synthesis and physical properties of hempseed and high-oleic hempseed oil estolides

Authors: Lin, Randy; Winfield, Demichael; ISBELL, PAUL - Oak Ridge Institute For Science And Education (ORISE); Evangelista, Roque; RAYMOND, BENJAMIN - Victory Hemp Foods, Pbc; Cermak, Steven

Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/19/2026
Publication Date: 1/30/2026
Citation: Lin, R.L., Winfield, D.D., Isbell, P.A., Evangelista, R.L., Raymond, B., Cermak, S.C. 2026. Synthesis and physical properties of hempseed and high-oleic hempseed oil estolides. Journal of the American Oil Chemists' Society. https://doi.org/10.1002/aocs.70049.
DOI: https://doi.org/10.1002/aocs.70049

Interpretive Summary: Hemp is an emerging crop grown in the United States with production values greater than $445 million in 2024, although new commercial applications are constantly being sought after to increase profitability. An investigation into a series of modified hemp seed oils was carried out by ARS researchers in Peoria, Illinois, to increase the demand of hemp into a potentially new bio-based commercial product. Hemp seed oil consists of unique fatty acids not often found in other crops grown domestically. With some chemical modifications to take hemp seed oils and transform them into a class of compounds called estolides, these products have been shown to be effective industrial lubricants. These materials had properties that made them perform extremely well in cold weather (winter) applications. Developing new industrial applications for hemp oil could enhance sustainability and profitability for U.S. farmers.

Technical Abstract: Hempseed oil (HSO) bears the unique property of its fatty acid profiles being unusually rich with polyunsaturated fatty acids. While the presence of numerous olefins would make this oil prone to oxidation, the presence of this functional group can be exploited to form oligomers called estolides, improving their oxidative stability and cold flow properties. In this work, a series of estolides were synthesized from HSO and high-oleic HSO (HOHSO) which are capped with fatty acids of varying chain length and esterified with 2-ethylhexanol (2-EH). The estolides capped with shorter chain saturated fatty acids (C8-C14) exhibited excellent cold flow properties, with pour points of -36°C and lower. Estolides prepared from HSO had higher kinematic viscosities than those prepared from HOHSO. HOHSO estolides bore physical properties similar to estolides synthesized from oleic-rich oils, which is advantageous for applications as bio-based motor oils. Furthermore, the HSO/2-EH estolide capped with a shorter chain fatty acid of the series synthesized (specifically caprylic/octanoic acid, C8:0) bore an unusually high kinematic viscosity compared to the rest of the series capped with longer chain fatty acids.