Enhance fire behavior of rigid polyurethane foam by intumescent flame retardants

Abstract Rigid polyurethane foam (RPUF) is the most widely used. Nonetheless, it is high ignitability. In order to guarantee safety, the incorporation of flame retardant is required. In this work, the improvement of flame retardant performance of RPUF is studied using layer by layer (LbL) techniques, containing intumescent flame retardant (IFR): Ammonium dihydrogen phosphate, Neopentyl glycol and Melamine in the ratio of 2:1:1 wt%. For the optimum coating condition, it was found that the ratio of polyethyleneimine and deionized water 1:2 wt% provided the suitable viscosity solution for coating and takes less drying time 30 min at 150 °C and 75 wt% of IFR capable of improving the flame retardant properties of RPUF. The result of ignitability test revealed that 75 wt% of IFR can effectively coat on RPUF and substantially improve its flame retardant properties by suppressing the melt dripping during flammability and immediately extinguishing flame after removing the ignition