Silica-coated metal-organic framework-β-FeOOH hybrid for improving the flame retardant and smoke suppressive properties of epoxy resin

In order to improve the flame retardancy and smoke suppression of epoxy resin (EP), ZIF-67 particles were loaded on beta-FeOOH by electrostatic action and coated with SiO2 to prepare SiO2@ZIF-67-beta-FeOOH (SZF). Scanning electron microscope (SEM) results showed that the SZF hybrid was successfully prepared. Different proportions of SZF were added to EP to study its combustion performance. The combustion results show that the limiting oxygen index (LOI) of the SZF composite with 5% flame retardant is increased to 31.9%, and the UL-94 flame retardant rating is increased to V-0. Peak heat release rate (pHRR), total heat release (THR), smoke release rate (SPR) and total smoke release (TSP) were reduced by 64.0%, 48.2%, 31.4% and 48.3%, respectively. According to the results of carbon analysis, the main flame retardant and smoke suppression mechanisms of SZF are analysed. In this work, a new idea is provided for improving the flame retardant and smoke suppression performance of EP.