Flame Retardant, Smoke Suppressant, and Thermal Degradation Properties of Poly(Vinyl Chloride) Treated With Fibrous Tin-Based Metal–Organic Framework

The current basic requirement for additive flame retardants is to improve flame retardancy while minimizing damage to the mechanical properties of the matrix. Many studies have reported that fibrous flame retardants not only improve flame retardancy but also enhance the performance of the flame-retardant polymer matrix. Therefore, a fibrous tin-based metal–organic framework material (SnBDC) in this study was prepared in an aqueous solution and studied as a flame retardant in poly(vinyl chloride) (PVC) matrix through the following methods: the limiting oxygen index (LOI), cone calorimetry, universal tensile testing machine, a thermogravimetric analyzer coupled with a mass spectrometer, scanning electron microscopy and X-ray diffractometer, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Compared with PVC, the LOI value and tensile strength of the flame-retardant PVC sample treated with 2 phr SnBDC (PVC/2) were increased by 3 units and 34%, respectively; the peak heat release rate, peak smoke production rate, and total smoke production of PVC/2 were reduced by 44%, 66%, and 45%, respectively. SnBDC mainly accelerates the dechlorination of PVC in the first stage, promotes the cross-linking of PVC dechlorination products into char, and inhibits especially the release of aromatic compounds.