The cause of instability
During the process of transesterification, if the reaction of fatty
acid is carried out with methanol, the result is methyl ester of that
fatty acid and if it is implemented with ethanol, ethyl ester is
formed. During the transesterification process, the fatty acid chain
remains unchanged; therefore the oxidation chemistry of biodiesel
is similar to that of the fatty acid or oil from which it is derived. It
becomes very important to study and understand the chemical
composition and structure of the fatty acids and their corresponding methyl or ethyl esters for the proper understanding of
the phenomenon of autoxidation