One-pot strategy to simultaneously prepare dyed, flame retardant and UV-resistant silk fabric based on a safflower yellow derivative

To give silk fabric multiple functions and improve its application range, a facile and eco-friendly one-pot technique was used to endow silk fabric with dyeing, flame retardant and ultraviolet (UV)-resistant performance based on a safflower yellow derivative. The structure, surface morphology, elemental composition, thermal properties and combustion behavior of the silk samples before and after modification were all characterized. In addition, the color depth and color fastness of the dyed silk (D-silk) and flame retardant silk (FR-silk) were evaluated and measured. The positive b* value in the CIELAB color space defined the yellow color of the dyed silk fabric. The char residue increased from 2.9 wt% of the original sample to 17.4 wt% of the FR-silk at 800 °C in air atmosphere. The limiting oxygen index (LOI) of FR-silk increased from 23.3% of the control sample to 32.8% with an increase of 40.7%. The peak of heat release rate (pHRR) and total heat release (THR) of FR-silk were much lower than that of the original sample. Furthermore, the UV protection factor (UPF) of FR-silk was 73.79, indicating excellent UV-resistance properties. The preparation process was green and environment-friendly, and the FR-silk had a good application prospect.