Superior flame retardancy and smoke suppression of poly (vinyl chloride) composites with iron/tin‐doped bismuth oxychloride.

Doping is a simple and effective method to change material properties. In this work, in order to improve the flame retardant performance of bismuth oxychloride (BiOCl) nanosheets in poly (vinyl chloride) (PVC), for the first time, iron and tin ions were doped into BiOCl (Fe‐BiOCl and Sn‐BiOCl) via a doping approach, respectively. X‐ray diffraction and morphology characterization confirmed that the Fe and Sn ions were doped into the BiOCl lattices, respectively. After doping, PVC composites obtained superior flame retardancy and smoke suppression. With the adding amount of 3 wt% Fe‐BiOCl and Sn‐BiOCl, the UL‐94 test rating of the PVC composites reached V‐0, and the peak of heat release rate reduced by 38% and 34%, total smoke production decreased by 55% and 42%, respectively, compared to neat PVC. Thermogravimetric and Thermogravimetric‐Fourier Transform Infrared results showed that Fe or Sn doping could further reduce organic volatiles in the gas‐phase and improve char residual in the condensed phase, both of which contribute to reducing fire hazards. Tensile properties and tensile modulus of PVC composites increased. In short, it is an economically effective approach targeting to improve the comprehensive properties of PVC through doping Fe or Sn into BiOCl. [ABSTRACT FROM AUTHOR]