In the first degradation, the extrapolated onset temperature (T 0 ) was measured, which denotes the temperature at which the weight loss begins and is specified to be used by ASTM 2550 . The addition of MEPECO of 5% improved the thermal stability from 652.29 K of VE_Neat to VE_5% MEPECO, 654.85 K at weight loss. The addition of MEPECO indeed improved the thermal stability by losing much less weight compared with VE_Neat. This was also proved by the slope of the line (k), for which VE_5%MEPECO registered at 4.03 min -1 compared to VE_Neat, 3.06 min -1 . The t 1/2 confirmed that even though the concentration of the samples reduced shortly from 0.17 to 0.23 minutes upon the addition of 5% MEPECO to VE, because of the presence of less moisture and the aliphatic compounds, crosslinking and filling of 5%MEPECO into VE were controlled, and the presence of the inherent flame-retardant property of 5%MEPECO induced a much lower weight loss at the onset temperature. Here, the increased activation energy induced by VE_5% MEPECO at 3.353 x 10 4 Jmol -1 and VE_neat at 2.545 x 10 4 Jmol -1 proved that the addition of MEPECO produced greater thermal stability, which means more energy is needed to degrade the inter-and intramolecular bonding of the VE upon exposure to heat. Looking at the entropy at -270.30 Jmol -1 K -1 for VE_5%MEPECO, which is much higher than -282.95 Jmol -1 K -1 for VE_neat, only shows that the presence of MEPECO triggered a faster catalyst that enchained together many monomers in a macromolecule and induced the formation of the interaction between the terminal groups of vinyl ester resin and MEPECO.