Insightful investigation of smoke suppression behavior and mechanism of polystyrene with ferrocene: An important role of intermediate smoke

Summary Aiming to investigate the smoke suppression mechanism of ferrocene in model polystyrene (PS) during combustion, we exploited the vapor‐phase and condensed‐phase behaviors. Cone calorimeter testing result showed that 3 wt% ferrocene imparted PS with 56.9% reduction in total smoke production. The analysis of the char after cone calorimeter testing demonstrated that the condensed‐phase smoke suppression mechanism was weak owing to the absence of charring behavior. The vapor‐phase mechanism was focused on the analysis of the small‐molecule smoke precursors and initially formed smoke intermediates. Transmission electron microscopy of initially formed smoke intermediates of PS/3Ferrocene revealed that enormous γ‐Fe2O3 nanoparticles from ferrocene participated in the initial formation of smoke intermediates, which subsequently underwent notable thermal oxidation degradation with decreased smoke residue. Thermogravimetric analysis coupled with Fourier transform infrared spectroscopy results manifested that the small‐molecule smoke precursors remained almost unchanged with addition of ferrocene. Conclusively, the smoke suppression mechanism with ferrocene predominantly originated from the intensive thermal oxidation of smoke intermediates, which opened a viable route for excellent smoke suppression design.