Authors:B. Lin, L. Yang, H. Dai, Q. Hou, and L. Zhang
Soybean oil based polyols (5-OH polyol, 10-OH polyol and 15-OH polyol) were synthetised from epoxidized soybean oil. The melting
peak of polyols and the relationship between melting peak and the number-average functionality of hydroxyl in polyols were
investigated by differential scanning calorimetry (DSC). The thermal decomposition of polyols and some of their thermal properties
by thermogravimetry (TG) and derivative thermogravimetry (DTG) were also studied. The thermal stability of polyols in a nitrogen
atmosphere was very close hence they had a same baseplate of triglyceride for polyols. The extrapolated onset temperature
of polyols in their thermal mass loss, first step had a decreasing order: 5-OH polyol>10-OH polyol>15-OH polyol due to the
difficulty in forming multiple elements ring of them had the same order.
The thermal behavior of polyols under non-isothermal conditions using Friedman’s differential isoconversional method with
different heating rates indicated that the 5-OH polyol had the lowest activation energy in thermal decomposition amongst these
polyols according to the same fractional mass loss because of the weakest intramolecular oligomerization. The 15-OH polyol
was prior to reach the mass loss region because the six-member ring is more stable than the three-member ring from 10-OH polyol
and more easily formed.
Authors:Michelle G. Mothé, Leni F. M. Leite, and Cheila G. Mothé
Figure 1 shows Friedman analysis for the three asphalt binders samples studied. In Fig. 1 a, it can be observed only one peak, which occurs around 431–473 °C. The presence of a peak by Friedman’sanalysis shows that the decomposition for sample (C
DTG curve ( Fig. 5 d) fits well with the first two energy vales in the activation energy plot ( Fig. 9 b). To validate the result of Friedman’sanalysis, an activation energy plotted from isoconversional integral method, OFW analysis, was calculated