Fire Hazard Mitigation in Bi-Continuous Phase Polymer Composites: Surface vs. Bulk and Experimental vs. Computational

Abstract

Selective localization of functional additives on the surface of bi-continuous phase polymer composites has proven effective in enhancing bulk properties, such as fire resistance, without additional additive usage. However, the extent and limitations of this functional surface effect on bulk performance remain unclear. To address this, we fabricate bi-continuous phase polymer composites with tunable surface chlorine, surface expanded graphite (EG), and bulk chlorine content, systematically evaluating their fire safety through experiments and simulations. While increased surface EG content improves initial thermal stability, its influence on real combustion is minimal. Instead, bulk chlorine content governs combustion behavior, elevating the limiting oxygen index and smoke generation while suppressing heat release. Fire dynamics simulation results corroborate experimental findings, and evacuation simulations reveal smoke generation as the dominant factor restricting escape. This study advances the understanding of fire safety mechanisms in polymer composites, offering a foundation for the development of next-generation flame-retardant composite material with reduced toxic emissions.