Fire retardancy of emulsion polymerized poly (methyl methacrylate)/cerium(IV) dioxide and polystyrene/cerium(IV) dioxide nanocomposites

► We prepare PMMA and PS containing ceria. ► Characterization by XRD and TEM shows that some of the ceria is well-dispersed in the polymers. ► The addition of ceria to both polymers leads to reduced thermal stability. ► In PMMA, the fire retardancy is enhanced but there is little effect in PS.