The initial products of oxidation are peroxides
and hydroperoxides which further degrade into shorter chain
products such as aldehydes, alcohols, ketones, and low molecular
weight acids[39–41]. There may also be the formation of highermolecular-weight products due to tendency of double bonds to
polymerization-type reactions. This leads to formation of insoluble
compounds and increase in the viscosity of biodiesel which can
cause choking of fuel lines and pumps. According to one study
[42], these polymers are insoluble in the petrodiesel-biodiesel
blends