Graphite-like Carbon Nitride/Polyphosphoramide Nanohybrids for Enhancement on Thermal Stability and Flame Retardancy of Thermoplastic Polyurethane Elastomers

Many efforts have been made to enhance the fire safety of thermoplastic polyurethane elastomers (TPUs) by reducing the heat release rate and smoke emission. Suppressing the emission of smoke and reducing toxic gases generated in the case of TPU burning play a key role to enable TPU meet the eco-friendly and safety requirements. In this work, poly diaminodiphenyl phosphonic methane (PDMPD) with higher thermal stability and catalytic char formation capacity was synthesized; graphitic carbon nitride/PDMPD (CPDMPD) hybrids were fabricated, and their effect on the thermal behavior and flame retardancy of TPU composites was studied. The peak heat release rate (PHRR), the total heat release, the CO yield, and the smoke release of TPU show an obvious reduction on account of addition of CPDMPD hybrids according to the cone tests. TPU/CPDMPD4 is endowed with a reduction of 49.0% of the PHRR. In this work, molecular designing and physical function are integrated to prepare versatile additives of polymers with optimized thermal stability and flame retardancy.