Synergistic effect of hydroquinone bis(di-2-methylphenyl phosphate) and novolac phenol in ABS composites

A new phosphorus-containing flame retardant hydroquinone bis(di-2-methylphenyl phosphate) (HMP) was successfully synthesized and characterized by 31P NMR and Fourier transform infrared spectroscopy (FTIR). The crystallization and melting point was measured by wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) separately. HMP was applied to prepare acrylonitrile-butadiene-styrene (ABS)/HMP/novolac phenol (NP) composites. The limiting oxygen index (LOI) value of ABS/HMP/NP composites increased with a decreasing ratio of HMP to NP, then declined with a further decrease in the ratio. The ABS/HMP/NP-3 had an LOI value of 33.5 and passed the vertical burning tests (UL-94) V-I rating at the ratio of HMP to NP was 2 to 1, when the synergistic effect of HMP and NP in the ABS composites was especially obvious, which were carefully characterized by thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).