Thermal degradation of urethane modified polyisocyanurate foams based on aliphatic and aromatic polyester polyol

Combustion of polyurethane foams releases toxic gaseous products. Therefore, decreasing the flammability of polyurethane foams is of practical significance to public health and the environment. The reported study investigated the thermal stability of urethane modified polyisocyanurate foams based on the presence of aromatic, aliphatic polyester polyol and polyether polyol moieties. Thermogravimetric analysis and differential scanning calorimetry demonstrated that the foam containing the lowest isocyanate index (220) and the lowest molecular mass of polyether polyol (200) was the most flammable (35% of char residue). Furthermore, the foams which contained a high molecular mass of polyether polyol (2000) and high isocyanate index (460) experienced fire performance (45% of char residue) similar to those foams containing aliphatic and aromatic polyester polyol (41 and 44% of char residue respectively).