A new type of charring agents

triazine-based crosslinked polymers

was synthesized through a polymeric reaction of trisglycidylisocyanurate and melamine in a melt state

and displayed good thermal stability and water resistance.The preparation process was feasible at ease

free of solvents and harmful released materials.The generated polymer was combined with ammonium polyphosphate(mass ratio 1∶5) to offer an intumescent flame retardant

which further was applied to polypropylene for flame retardant tests.When the intumescent flame retardant was loaded with 32% mass of the flame retarded polypropylene

burning tests and analysis showed that the resultant char layers exhibited continuous and compact structures

the oxygen limited index was 32

the vertical burning reached FV-0 level

and the peak heat release rate was 486 kJ/m2

in comparison with pure polypropylene

decreased by 47.5%

while the burning time with flame 714 s increased by 54.9%.