Phosphorylation of sodium copper chlorophyll enables color-fasten and durable flame retardant wool fibers

In order to develop a kind of color-fasten and durable flame retardant wool fibers , the green and environmentally friendly dye, i.e. sodium copper chlorophyll (SCC) was firstly used to dye the wool fibers, then the dyed wool fibers (DW) was phosphorylated with phosphoric acid to obtain flame retardant wool fibers (FR-W). The results show that FR-W has good color fastness, and the limiting oxygen index (LOI) of FR-W is still as high as 29.6% after 50 times washing, indicating excellent durable flame retardant performance. The char residue of FR-W at 800 °C under air atmosphere is 27 wt%, showing good char forming ability. Compared to the control sample, the peak of heat release rate (pHRR) of FR-W decreases by 65% and the total heat release (THR) of FR-W decreases from 5.2 MJ/m 2 to 4.8 MJ/m 2 . The SCC combined with phosphate groups play the role of gas and condensed phase flame retardant mechanism.