Synergistic flame retarded poly(methyl methacrylate) by nano-ZrO2 and triphenylphosphate

The synergistic flame-retarded systems consisting of nano-ZrO₂ and triphenylphosphate(TPP) for poly(methyl methacrylate)(PMMA) are reported. The synergistic effects were studied by cone calorimeter test, thermal gravimetric analysis (TG), Raman spectra, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The synergistic effect of nano-ZrO₂ with TPP could be clearly observed by cone calorimeter test. The Raman spectra, SEM, and XPS results provide evidence that nano-ZrO₂ can efficiently promote the formation of charred layers composed of varying amounts of graphite and amorphous carbon. The possible mechanisms for synergy are discussed.