Combination of gas and condensed phase effect of phosphorus flame retardancy in polyisocyanurate- polyurethane foam

摘要

the main aim of this work was to develop high efficient phosphorus-based flame retardant system for rigid polyurethane foam. Ammonium polyphosphate (APP) and dimethyl methyl phosphonate (DMMP) were chosen to prepare flame-retardant polyisocyanurate modified polyurethane (PIR-PUR) foams. The flame retardant, thermal degradation and combustion properties of PIR-PUR foams were characterized by limiting oxygen index (LOI) test, vertical burning (TL-94) test, thermogravimetric analysis (TGA), cone calorimeter (Cone) and microscale combustion calorimeter (MCC), respectively. The LOI results showed that the combination of APP and DMMP in PIR-PUR foam possessed higher flame retardancy. Cone results indicated that the presence of DMMP can delay the ignition of specimen and delay the time to reach the maximal PHRR. The gases generated during the thermal decomposition process were investigated by thermogravimetric analysis/infrared spectrometry (TG-IR). Moreover, the mechanical performance and thermal insulating properties are evaluated.