Fabrication of flame-retardant and smoke-suppressant rigid polyurethane foam modified by hydrolyzed keratin

Abstract Rigid polyurethane foam (RPUF) has been fabricated and modified by hydrolyzed keratin to improve its flame retardancy and smoke suppression. Then, the limiting oxygen index (LOI), cone calorimeter (CONE), thermogravimetric analyzer and scanning electron microscope (SEM) were used to characterize the modified RPUFs. It was found that the LOI of the modified RPUFs increased with the presence of hydrolyzed keratin. In addition, the peak heat release rate (PHRR) and total heat release (THR) of the modified RPUF tended to decrease. The HRR of RPUF-HK5 reduced 28.8 kW/m 2 compared with RPUF-0, and the THR of RPUF-HK5 was 0.74 MJ/m 2 lower than that of RPUF-0. RPUF-HK5 had the most obvious smoke suppression effect. Compared with RPUF-0, the smoke density (Ds) and light transmittance (T) of RPUF-HK5 decreased by 8.88 and increased by 11.26%, respectively. The current research results showed that hydrolyzed keratin can improve the flame-retardant and smoke-suppression performances of RPUFs and that 5 wt% hydrolyzed keratin was the most suitable ratio for the modified RPUF.