Effect of Phosphorus Compounds on Flame Retardancy and Thermal Degradation of Polycarbonate and Acrylonitrile–Butadiene–Styrene

Abstract

Phosphorus flame retardants, bis(2,6-dimethylphenyl) phenyl phosphonate (BDMPP) and poly(bisphenol S phenyl phosphonate) (PBSPP), were synthesized and their structures were characterized with Fourier transform infrared spectroscopy, and 1H and 31P nuclear magnetic resonance. The phosphorus compounds were used to impart flame retardancy to polycarbonate (PC) and acrylonitrile–butadiene–styrene (ABS). Combustion behaviors and thermal degradation properties of the systems were assayed by limiting oxygen index (LOI), vertical burning test (UL-94), and thermogravimetric analysis. PC/7 wt.% BDMPP and PC/5 wt.% PBSPP pass UL-94 V-0 rating; their LOI values were 32.7% and 33.6% respectively. ABS/35 wt.% BDMPP and ABS/30 wt.% PBSPP also pass the UL-94 V-0 rating and their LOI values were 28.9% and 28.3% respectively. Scanning electron microscopy revealed that the char properties had direct effects on flame retardancy.