Alkali lignin as a carbonization agent on the thermal degradation and flame retardancy of intumescent flame retardant coating

The influence of alkali lignin (AL) as a carbonization agent on the thermal degradation and flame retardancy of intumescent flame retardant (IFR) coating was investigated under air condition, with ammonium polyphosphate (APP) as an acid source, and melamine (MEL) as a blowing agent. Compared with a traditional APP/pentaerythritol (PER) /MEL IFR system, thermogravimetric analysis (TGA) results showed that APP/AL/MEL IFR system could induce the synergistic effect at a much boarder temperature range, and improve the thermal stabilities of the IFR coating. With the increase of AL loading, cone calorimeter test showed the peak heat release rate of the IFR coatings decreased from 54.86 MJ/m(-2) to 41.06 MJ/m(-2).