Smoke suppressant and fire-retardant polyurethane-polyisocyanurate (PIR) foam

In this study, the combinations of phosphorous-containing fire retardants such as triethyl phosphate, oligomeric triethyl phosphate, diethyl ethyl phosphonate, diethyl hydroxymethyl phosphonate, ammonium polyphosphate, and smoke suppressant zinc borate were used as additives in order to produce non-toxic smoke suppressant and fire-retardant rigid polyurethane-polyisocyanurate (PIR) foams. Flame height and smoke density of polyurethane-polyisocyanurate foam decreased by incorporating different combinations of combustion modifiers in PIR formulations. The smoke suppressant was zinc borate. The combination of zinc borate with triethyl phosphate, oligomeric triethyl phosphate, and diethyl hydroxymethyl phosphonate resulted in a good synergy. The cone calorimeter analysis showed that the best combinations were zinc borate (10.1%) and triethyl phosphate (13.7%), or zinc borate (10.1%), triethyl phosphate (6.9%), and oligomeric triethyl phosphate (7%) and they decreased the burning and smoke formation rate of PIR foam. These combinations may be applied to produce fire-retardant PIR foam in the industry.