A study of the combustion and fire-retardance behaviour of unsaturated polyester/phenolic resin blends

The thermal degradation and combustion behaviour of an interpenetrating net work (IPN) structure of unsaturated polyester UP resin and a resole type of phenolic resin was studied. Thermal gravimetric analysis (TGA) was used to monitor the degree of thermal decomposition for the UP/phenol IPN structur e and the change of the oxygen index (OI) was used to describe the variatio n of the combustion behaviour. The smoke density was measured via a non-fla ming process to detect the amount of smoke generated during the combustion. A homemade cone calorimetric dynamic flammability evaluation system was as sembled to analyse the gas evolved and to measure the heat release rate (HR R) during the combustion. Under simulated conditions of a burning field at the temperature of 757 degreesC, the variation of the concentration of carb on monoxide (CO) and the HRR of the UP/phenol IPN structure were studied. T he results show that modification of the essentially flammable UP resin by the phenol structure to form an IPN system cannot only remarkably improve t he heat resistance but also help to suppress the smoke, toxic gas and heat release during the combustion. (C) 2000 Elsevier Science Ltd. All rights re served.