Flame Retardant and Mechanical Properties of Toughened Phenolic Foams Containing a Melamine Phosphate Borate

A melamine phosphate borate flame retardant was prepared through a solvothermal method and characterized by Fourier transform infrared spectroscopy, scanning electron microscope, element analysis, and X-ray photoelectron spectroscopy. The incorporation of melamine phosphate borate into the phenolic foams toughened by polyethylene glycol results in an increase in limiting oxygen index and a decrease in peak heat release rate, smoke, and CO and CO₂ production. The mechanical tests reveal that the incorporation of melamine phosphate borate leads to a further improvement in flexural strength and compressive strength, and a decrease in the pulverization ratios of the toughened foams. Moreover, the thermal stability of the toughened PF foams containing melamine phosphate borate was studied.