Location: Bio-oils Research Unit
Title: Oxidative stability of estolide esters using PDSC Authors
Submitted to: Society of Tribologists and Lubrication Engineers
Publication Type: Abstract Only
Publication Acceptance Date: December 17, 2013
Publication Date: May 18, 2014
Citation: Sharma, B.K., Biresaw, G., Cermak, S.C., Isbell, T. 2014. Oxidative stability of estolide esters using PDSC [abstract]. Society of Tribologists and Lubrication Engineers Annual Meeting & Exhibition. p. 52. Technical Abstract: Estolides are obtained by the formation of a carbocation that can undergo nucleophilic addition with or without carbocation migration along the length of the chain. The carboxylic acid functionality of one fatty acid links to the site of unsaturation of another fatty acid to form oligomeric esters. The estolide carboxylic acid functionality can then be converted to the corresponding estolide ester under esterification conditions with the addition of an alcohol. It has been shown earlier that estolide esters have improved oxidative stability over vegetable oils and have also overcome other shortfalls associated with vegetable oils, such as low hydrolytic stability and poor low temperature properties. In this study, three different methods of measuring oxidative stability were compared for a series of estolide esters additized with three antioxidants (a hindered phenol and two alkylated diphenyl amines). These methods were oxidative stability index (OSI), rotating pressurized vessel oxidation test (RPVOT), and pressurized differential scanning calorimetry (PDSC).