The role of dispersion of LDH in fire retardancy: The effect of dispersion on fire retardant properties of polystyrene/Ca−Al layered double hydroxide nanocomposites

In order to clarify the role of dispersion on the fire retardant properties of polystyrene/LDH nanocomposites, two types of composites were prepared. The largely exfoliated polystyrene/Ca−Al−LDH−B nanocomposites (PS/Ca−Al−LDH−B) were prepared by in situ bulk polymerization while PS/Ca−Al−LDH−B composites were prepared by melt blending. X-ray diffraction and transmission electron microscopy were used to characterize the morphology of the samples while the thermal stability and fire properties were studied by thermogravimetric analysis and cone calorimetry. Good dispersion of LDH in the PS matrix was obtained by in situ bulk polymerization and those nanocomposites showed better thermal and fire properties compared to the composites with poorly-dispersed LDH obtained by melt blending.