Enhancing flame retardancy and promoting initial combustion carbonization via incorporating electrostatically surface-functionalized carbon nanotube synergist into intumescent flame-retardant poly (butylene succinate)

Fire safety is becoming more stringent in the use of polymers. In spite of introducing intumescent flame retardants (IFRs), poly(butylene succinate) (PBS) still presents fast fire growth and continuous combustion. Based on the contribution of the one-dimensional synergist to melting-dripping suppression and flame retardancy enhancement, aminated multi-walled carbon nanotube was first electrostatically attached by ammonium polyphosphate (APP), and hence promote carbonization in the char mass of 65.7% during combustion for the IFR system of PBS/APP/pentaerythritol (PER). Furthermore, total heat release (THR) and average mass loss rate (AMLR) reduced by 79.6% and 93.8%, respectively. The flame retardancy mechanism was mainly ascribed to highly thermal stability of char during initial fire growth and simultaneous formation of continuous char layer thereof. So it is inspired that flammable feature of polymers might be rationally utilized to promote flame retardancy.