Constructing Co-decorated layered double hydroxide via interfacial assembly and its application in flame-retardant epoxy resin

Aiming to improve the agglomeration and low efficiency of MgAl-layered double hydroxides (MgAl-LDH) for epoxy resin, a hybrid LDH (LDH@Co-LDH) was prepared through organic intercalated and interfacial assembly. It confirmed that Co-LDH displayed a spherical structure and well decorated on the intercalated MgAl-LDH. The resulting LDH@Co-LDH not only improved the flame retardancy of epoxy resin (EP) but also increased the glass transition temperature by 26 °C. Specifically, EP composite with only 2 wt% LDH@Co-LDH passed the UL-94 V-0 rating with a 54% reduction in the peak heat release rate and a 24% reduction in total smoke production compared to EP. Mechanism studies illustrated that the improved fire safety was attributed to the optimized char layers resulting from the interfacial charring reactions. The interfacial assembly provides a promising approach for preparing hybrid LDH to enhance the fire safety of polymers.