Fabrication and characterization of flame‐retardant and smoke‐suppressant of flexible polyurethane foam with modified hydrotalcite

Abstract The hydrotalcite has been chemically modified by using the ion exchange method to insert dihydrogen phosphate between the carbonate‐type magnesium–aluminum hydrotalcite layers. And then, the effect of modified hydrotalcite on the flame retardancy and smoke suppression properties of flexible polyurethane foam (FPUF) has been investigated using limiting oxygen index (LOI) method, cone calorimeter test (CONE), smoke density chamber, flue gas analyzer, and scanning electron microscope (SEM). The current indicated that the LOI of flame‐retardant modified FPUF was increased to 25.4%. And the peak heat release rate (PHRR) and total heat release (THR) of the samples were decreased by 74.9 kW/m 2 and by 9.7 MJ/m 2 , respectively. Additionally, the total amount of flue gas produced by combustion was reduced by 157.7 m 2 /m 2 , and the maximum concentration of carbon monoxide (CO) gas decreased from 51.3 to 23.8 mg/m 3 . Based on these data, it can be found that the hydrotalcite modified by dihydrogen phosphate intercalation had an excellent flame‐retardant and smoke‐suppressant effect, and 15% of modified hydrotalcite was the most appropriate amount during the combustion process of the modified FPUFs.