Rigid polyurethane foams co-modified with chicken feather protein and expandable graphite

Rigid polyurethane foam (RPUF) was prepared by synergistic modification using self-made chicken feather protein as well as expandable graphite (EG). The flame retardancy and smoke suppression of the modified RPUFs were analyzed based on the heat release rate (HRR), total heat release (THR), smoke production rate (SPR), and total smoke release (TSR). The HRR, THR, SPR, and TSR of RPUF5 with 5 g of EG were 18.7 kW/m 2 , 1.35 kW/m 2 , 0.0028 m 2 /s, and 21.2 m 2 /m 2 , respectively, which showed the best performance at a thermal radiation intensity of 25 kW/m 2 and showed a decrease of 42.8%, 35.4%, 66.3%, and 56.3% compared with the pure sample RPUF1. In addition, four methods were used to calculate the activation energy (E) of the modified RPUFs, which showed that RPUF5 had the highest E and the best thermal stability. At the same time, RPUF5 also had good mechanical properties. These results will lay the foundation for the development and application of RPUF in the flame retardant field.