Enhancing anti‐meltdrop and smoke suppression properties of flame retardant poly(ethylene terephthalate) fabric by fiber‐blending method

Abstract Flame retardant poly(ethylene terephthalate) (FRPET) fabrics are widely used in daily life. However, the meltdrop and visible smoke produced during combustion significantly limit its further application. This study proposes a simple but effective method of fiber‐blending to improve the above shortcomings. On the basis of synergistic flame retardancy of nitrogen and phosphorus, the FRPET was blended with flame retardant viscose (FRV) and intrinsic nitrogen‐containing flame retardant fibers (NIFRFs), to prepare the binary and ternary blended FRPET samples labeled as NIFRF/FRPET and FRV/NIFRF/FRPET, respectively. The limiting oxygen index and cone calorimeter test show that the ternary‐blending could effectively suppress the combustion of FRPET fiber composite. The smoke density test and UL‐94 vertical combustion test indicate that ternary‐blending could better improve the meltdrop characteristics and smoke suppression property than binary‐blending. Among all samples, FRV/PMIA/FRPET (1:4:5) owns the highest LOI of 32.6% and lowest smoke density of 61.37. The investigation of residual char utilizing scanning electron microscopy, the X‐ray photoelectron spectroscopy and the Laser Raman spectroscopy demonstrates that the FRPET meltdrop would adhere to the surface of component fibers to avoid droplets. Besides, fiber‐blending could increase the yield and degree of graphitization of residual char, which is conducive to improving samples' flame retardancy through the condensed phase. This work may provide a workable strategy to expand the application areas of FRPET fabrics.