(115c) Phosphate intercalated layered double hydroxide as potential flame retardants for polystyrene

The need to produce zero-energy buildings is becoming more popular in the context of energy resource conservation and demand reduction. Recently, the growing surge in the application of lightweight foamed concrete in the building sector, highlights an underlying potential in this area. Styrofoam beads (foamed polystyrene beads) are the commonly used material for such applications because of their low cost, availability, and thermal insulation property. However, polystyrene is highly flammable, and thus poses a safety risk. In this study , polystyrene was compounded with LDH (based on Al⁺, Mg⁺ & Zn⁺) and phosphate intercalated LDH to improve its flame retardance. LDH were synthesized by co-precipitation method and phosphate intercalation was achieved by ion-exchange method. The resulting composite were tested for its flame resistance by limiting oxygen index (LOI) and thermal stability. The limiting oxygen index was increased by nearly 5 % along with reduced flame spread, smoke generation and dripping. Overall, the study highlights the potential of modified LDH as a flame retardant for polystyrene and replacing the currently used halogenated flame retardants which are not environmentally friendly.