Preparation of flame retardant and anti-dripping PET fabric based on sodium copper chlorophyllin dyeing, UV grafting and phosphorylation

The traditional flame retardant polyester fiber containing phosphorus has serious melt droplet phenomenon, and its flame retardancy will be greatly decreased after dyeing, which seriously restricts its wide application. To address the issue, PET fibers were dyed by sodium copper chlorophyllin (SCC) at high temperature to prepare dyed PET fibers (DPET) with dyeing and anti-dripping properties. To further improve the flame retardancy of DPET, N-hydroxymethylacrylamide (NMA) was UV-grafted to DPET (DPET-g-NMA), which was then chemically modified by diammonium hydrogen phosphate (DAP) through high-temperature esterification reaction to obtain flame retardant PET fibers (FR-PET). The results showed that the char-forming ability of FR-PET was higher than that of DPET, and the melt droplet was effectively suppressed. In addition, the heat release rate (HRR), the peak of heat release rate (PHRR), and the total smoke production (TSP) of FR-PET were all significantly reduced, showing good flame retardancy. This work developed a simple and green strategy to improve the flame retardancy and anti-dripping performance of PET fiber without subsequent dyeing, showing great application prospects.