Analysis of the oxidative degradation of biodiesel blends using FTIR, UV-Vis, TGA and TD-DES methods

In this paper, the analysis of the oxidative degradation of biodiesel blends were explored using the following instrumental methods: Fourier transform infrared spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-Vis), thermogravimetric analysis (TGA) and two-channel and differential dielectric spectroscopy (TD-DES). During the degradation process, a good consistency could be observed between the change of the dielectric property and that of the Rancimat conductivity, infrared peak area, ultraviolet absorbance and the residual mass. The increase of these parameters was not significant before the end of the induction period, after which they rose sharply, indicating that all these analytical methods were suitable for monitoring the degradation process of the biodiesel blends. The TD-DES technique exhibited excellent prediction performance for FTIR, UV-Vis and TGA in assessing the extent of oxidative deterioration.