Fabrication of expandable graphite and soybean oil-based synergistic modified polyurethane foam with improved thermal stability and flame retardant properties

Abstract

Abstract Biomass soybean oil-based polyol rigid polyurethane foam (RPUF) was modified and prepared by expandable graphite (EG). The effects of EG on the thermal stability and flame retardant properties of soybean oil-based polyol RPUFs were investigated by thermogravimetric analysis, pyrolysis kinetic analysis, conical calorimetry and flue gas toxicity analysis. The results showed that modified RPUF (RPUF-4) with EG content of 20 wt% had the highest initial and end temperatures, the highest activation energy E, the lowest Ds (17.6), and the highest light transmittance (73.6 %). At the same time, RPUF-4 had the lowest heat release rate (10.1 and 16.5 kW/m2), the lowest total heat release (1.5 and 2.1 MJ/m2), and the lowest average toxic gas emissions. The current study indicated that RPUF-4 had better thermal stability and flame retardant performance, which provided a useful reference for subsequent biomass flame retardant modified RPUFs.