Fire resistance of phosphoric acid-based geopolymer foams fabricated from metakaolin and hydrogen peroxide

In this research, phosphoric acid-based geopolymer foams (PAGFs) are fabricated from metakaolin and phosphoric acid with hydrogen peroxide as a foaming agent. Properties of PAGFs are characterized by a series of tests, including porosity, dry bulk density, compressive strength, thermal conductivity, fire resistance, XRD and SEM. The porosity and dry bulk density of PAGFs are tightly dependent on the hydrogen peroxide content, which further influence the compressive strength, thermal conductivity and fire resistance. Moreover, the excellent high temperature stability of PAGFs is beneficial to the thermal conductivity and fire resistance. After 2 h fire resistance tests, the reverse-side temperatures except the PAGFs with 4% mass fraction of hydrogen peroxide still maintain around 220 degrees C. Therefore, PAGFs with extraordinary fire resistance have great potential for fire protection. (C) 2019 Elsevier B.V. All rights reserved.