Study On Combustibility of Urethane-Modified Polyisocyanurate Foam

The relation between components of urethane-modified polyisocyanurate foams and their combustion behavior was observed to compare with rigid poly urethane foams, using the specially designed burning test apparatuses. Accord ing to the vertical smoke-weight determination for chipped samples, almost all foams lost their weight at about 650 °C. The amount of generated smoke became maximum at about 500 °C for polyurethane foams and at about 600 °C for polyisocyanurate foams. According to the horizontal smoke-concentration deter mination for small plate samples, fires occurred with much amount of generated smoke at about 600 °C. Through both the testings, adoption of higher functional isocyanate, secondary polyol, lower molecular weight polyol, or amine catalyst brought much smoke generation. Polyisocyanurate foams showed little smoke as compared with polyurethane foams.