Fabrication of halogen-free and phosphorus-free flame retardant and antistatic PAN fibers based on tea polyphenol phenolic resin chelated with iron (Ⅲ) ions

Polyacrylonitrile (PAN) fibers are one of the three major synthetic fibers in the world, but the drawbacks of flammable and static charge accumulation limit their application. To address the issue, tea polyphenol phenolic resin (TPPR) was firstly prepared from biomass tea polyphenol in this paper. Next, TPPR was blended with PAN spinning solution and wet-spun with Fe3+ solution as coagulation bath to construct phosphorus-free and halogen-free flame retardant PAN fibers (TPPR@Fe/PAN). The results indicated that the limiting oxygen index (LOI) value increased from (17.3 ± 0.51)% of PAN fibers to (31.6 ± 0.51)% of TPPR@Fe/PAN. Even after 30 laundering cycles (LCs), the LOI value of TPPR@Fe/PAN was still up to (27.7 ± 0.51)%, indicating good washing durability. Additionally, the heat release capacity (HRC) and total heat release (THR) of TPPR@Fe/PAN had 35.0% and 48.6% reduction, respectively. Furthermore, TPPR@Fe/PAN obtained excellent antistatic ability. Besides, the TG-IR results demonstrated that both the release of flammable and toxic gases were significantly suppressed. In the work, a simple and feasible flame retardant and antistatic strategy was established which was convenient for fabrication of functional PAN fibers on a large scale.