Study on Preparation and Flame-Retardant Mechanism of Cerium-Doped Mg-Al Hydrotalcite

Cerium-doped hexagonal lamellar hydrotalcite was prepared via the hydrothermal method and applied to epoxy resin (EP) composites. The characterization results of cerium-doped hydrotalcite showed that the interlayer spacing of hydrotalcite increased with an increase in the cerium doping amount, and an appropriate amount of cerium doping will not destroy the layered structure of hydrotalcite. This study also determined the best cerium doping ratio. The combustion performance of the composite was studied using thermogravimetric infrared analysis, smoke density test, and limiting oxygen index (LOI). The results showed that the addition of cerium-doped hydrotalcite reduced the amount of smoke and the escape of hydrocarbons during the combustion and decomposition of epoxy resin. The main flame-retardant mechanism was that the addition of cerium-doped Mg-Al hydrotalcite promoted the formation of a dense protective layer on the surface of the composite to inhibit the escape of combustible substances, so as to achieve the purpose of a flame retardant and smoke suppression.