In this work, a novel lightweight metakaolin geopolymers were produced by using hydrogen peroxide as foaming agent. The influence of the hydrogen peroxide incorporation content (0.25 - 1.25%) on density, compressive strength and thermal conductivity was evaluated. The experimental results show that the density and compressive strength were decrease with increasing content of hydrogen peroxide. However, the thermal insulating properties of the geopolymer foams were improved with increasing content of foaming agent. Geopolymers exhibiting thermal conductivity as low as 0.172 W/mK and a density of 0.5 g/cm3 were produced, showing the potential of these materials in applications requiring lightweight and low thermal conductivity materials.
