One-step synthesis and flame retardancy of sheaf-like microcrystal antimony oxychloride

A mild and facile solution route has been developed for large-scale synthesis of sheaf-like antimony oxychloride Sb ₈O ₁₁Cl ₂ (H ₂O) ₆ microcrystal at room temperature. The morphologies and structures of the as-prepared products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A mechanism for the formation of the sheaf-like microstructure was tentatively proposed. The shape regulation was attributed to the capping mode of the PVP-directed antimony oxychloride crystal. The thermogravimetric and differential thermal analysis (TG/DTA) were employed to investigate thermal decomposition mechanism and temperature-dependent phase transition of antimony oxychloride Sb ₈O ₁₁Cl ₂ (H ₂O) ₆ in the air. The flammable property determined by the cone calorimeter showed excellent flame retardancy when applied this antimony oxychloride in poly (vinyl chloride) (PVC) polymer.