Mussel-inspired flame retardant coating on polyurethane foam

In this work, a mussel-inspired flame retardant containing a catechol moiety, was synthesized, which was used to coat flexible polyurethane foam (FPUF). The influence of the coating time, coating temperature, and flame retardant concentration on the coating thickness and morphology were investigated. When the temperature is 45 °C, and the coating time is 3 days and the concentration is 3 mg/mL, the peak heat release rate (PHRR) of the coated FPUF decreases by 44.2 %, and the combustion time was significantly prolonged. This is because catechol contains a large number of hydroxyl groups, and the flame retardant coating formed after polymerization contains a large amount of carbon sources. Additionally, the phosphorus element in DPDHPP has a catalytic effect on carbon formation, which can form a phosphorus rich 3D network carbon layer in the condensed phase during combustion. Catechol and P-containing free radicals can produce quenching effects in the gas phase, reducing the active free radicals in the air. The flame retardant coating formed not only significantly improves the flame retardant performance of FPUF, but also has no adverse effect on the compression properties of the FPUF.