Durable Flame-Retardant Cotton Fabric Modified by a Novel Reactive P-N Intumescent Flame Retardant

Table 6

The flame retardance of TTCTN(20)-CF with different washing cycles.

Washing cycles	After-flame time/s	After-glow time/s	Char length/mm	LOI/%	Flame retardant ratings
0	0.0	0.0	135	28.6 ± 0.28	B1
10	0.0	0.0	135	28.1 ± 0.34	B1
20	0.0	0.0	138	27.7 ± 0.20	B1
30	0.0	0.0	140	27.3 ± 0.32	B1
40	0.0	0.0	143	26.8 ± 0.26	B1
50	0.0	0.0	147	26.2 ± 0.28	B1
60	0.0	0.0	150	25.3 ± 0.32	B2