Biodiesel is defined as the
monoalkyl ester derivative of long-chain fatty acids, originated fro
m renewablesources, such as vegetable oils or ani
mal fats. The
most co
mmon use of biodiesel is direct substitution offossil fuels in co
mpression-ignition engines. The heating of vegetable oils can cause co
mple
mentarydeco
mposition reactions, in which the results can also lead to the for
mation of poly
meric co
mpounds. Thiswork has been carried out to study the degradation process of biodiesel in different te
mperatures and exposureti
mes. The degradation process of biodiesel affected its ther
mogravi
metric and calori
metric profiles, indicatingthe for
mation of inter
mediary co
mpounds. The spectroscopic data of degraded biodiesel suggested oxidativepoly
merization, confir
ming ther
mal data. In the degraded biodiesel at 210
![](/i<font color=)
mages/entities/deg.gif">C for 48 h, the for
mation of gu
moccurred, indicating that oxidative poly
merization was co
mpleted.