Efficient Catalytic Smoke Suppression for PVC by In Situ-Constructed ZnCl 2 Species from Layered Double Hydroxide

The widely used polymer materials are flammable, producing smoke as the main cause of casualties in fires. However, research to improve the fire safety of polymers mainly focuses on the improvement of flame retardant properties with smoke suppression as mostly an attached function, resulting in poor performance. Herein, we report a novel strategy for catalytic smoke suppression by constructing active sites via LDH lattice confinement coupled with an in situ halogen capture and release process. Specifically, Zn 2+ was accommodated in the LDH layer, further incorporated into PVC. PVC-released chlorine in combustion was in situ adsorbed by LDHs to form highly dispersed ZnCl 2 active species. Relative to LDHs without Zn 2+, smoke suppression performance was improved by 3 times. This is ascribed to ZnCl 2 presence as an active site catalyzing the generation of trans-olefins and char cracking, helping to produce volatile aliphatic hydrocarbons and reducing smoke amount, as affirmed by comprehensive analysis of spectroscopic characterizations and theoretical calculations.