Interpenetrating polymer networks were prepared from glycerol modified linseed oil, toluene-2,4-diisocyanate and cardanol based dye monomer with 2-chloroaniline. The expected course of reaction and structural analysis of such polymers were investigated by FTIR spectroscopy. Thermal stability along with exothermic and endothermic behavior of the polymer degradation was studied by thermogravimetric analysis (TGA), derivative thermogravimetry (DTG) and differential thermal analysis (DTA). The isothermal Freeman-Anderson method was used to calculate the order of the reaction (n) and activation energy (Ea) of the degradation process. The effect of variation of NCO/OH molar ratio and PU/CDM weight ratio on the thermal stability was studied.