Sensitivity of Heat of Reaction for Polyurethane Foams

The heat of reaction for the decomposition of polyurethane foam and its melt are determined from the heat flow measurements obtained through simultaneous differential scanning calorimetry and thermogravimetric analysis. Under nitrogen environment, the decomposition of foam experiences two endothermic pyrolysis reactions based on the experimental results. Through the investigation on the sensitivity of heat of reaction to heating rate and sample mass, a region where the heat of reaction remains constant is found for the melt samples tested. This consistent region includes heating rate from 5 to 20 °C/min and sample mass between ~20 and ~50 mg. No consistent region is found for the foam samples because of the reduced accuracy in the heat flow measured. For the foams and melts tested, the consistent heat of reaction for the second reaction ranges from endothermic 164 ‐ 295 J/g while the recommended heat of reaction for the first reaction ranges from endothermic 610 ‐ 1023 J/g.