AbstractPolyester resins were prepared from chlorendic acid, maleic anhydride, and ethylene‐ and/or propylene‐glycol. The resins were cured at room temperature with two different crosslinking agents including styrene and methyl methacrylate. The thermal behaviour of these polyester resins and their cured products was studied. From the thermogravimetric data it was observed that the polyester resins cured with styrene are thermally more stable than the methyl methacrylate cured products. It was also observed that the polyester resin prepared from propylene glycol is thermally more stable relatively than the ethylene glycol based polyester resin. The activation energies of thermal degradation of the resins and their cured products were calculated. The implications of these results are discus