Fire behaviour assessment of rigid polyurethane foams containing nanoclay and intumescent flame retardant based on cone calorimeter tests

In this study, nanoclay was incorporated into rigid polyurethane foams at different loadings, namely 5 wt. %, 10 wt. % and 15 wt. %, to enhance the fire resistance of the foams. In addition, an intumescent flame retardant composed of ammonium polyphosphate/pentaerythritol was additionally introduced to generate a synergistic positive effect on the fire resistance of the foams. The fire behaviour of the foams containing nanoclay with and without the intumescent flame retardant was investigated by using a cone calorimeter. The experimental results showed that the fire resistance of the rigid polyurethane foams could be enhanced with increasing the nanoclay loading in the foam. Furthermore, it was found that the nanoclay had a good synergistic effect with the intumescent flame retardant in the rigid polyurethane foams in terms of fire resistance. © 2019 University of Chemical Technology and Metallurgy