Synergistic effects of ZrO2 or B2O3 on flame-retarded poly(butyl methacrylate) with tricresylphosphate

The synergistic flame retarded systems consisting of ZrO2 or B2O3 and tricresylphosphate(TCP) for poly(butyl methacrylate)(PBMA) are reported. The synergistic effects were studied by limited oxygen index (LOI) test, UL-94, thermal gravimetric analysis (TGA), Infrared Spectroscopy (IR), Raman spectra and digital photos. The synergistic effect of ZrO2 or B2O3 with TCP could be clearly observed by LOI. The TGA results show that ZrO2 or B2O3 increases the char yields of the systems at 500 degrees C. The Raman spectra, IR and digital photos results provide evidence that ZrO2 or B2O3 can efficiently promote the formation of charred layers composed of varying amounts of graphite and amorphous carbon. The possible mechanisms for synergy are discussed. Copyright (C) 2010 John Wiley & Sons, Ltd.