Intumescent coatings based on alkali-activated borosilicate inorganic polymers

This paper presents results regarding the possibility of using intumescent alkali-activated borosilicate inorganic polymers (AABSIP), obtained by alkali activation of waste glass powder with mixtures of NaOH, KOH, and borax, as passive fire protection for various substrates. In order to verify the fire behavior, four types of AABSIP intumescent coatings were applied on metal plates and commercial plasterboard and tested in direct contact with a propane flame. The presence of intumescent AABSIP coatings on the metal plates kept the temperature below 500°C (measured on the opposite face where the propane flame was applied); this temperature was critical for the structural strength of steel. AABSIP coating decreased the propagation rate of plasterboard substrate degradation as well as the thermal transfer through the plaster substrate.