A high melting temperature phosphorus flame retardant

hydroquinol bis(diphenyl phosphate) (HDP)

was synthesized in a novel process.First

the intermediate product was synthesized from hydroquinone and phosphoryl oxychloride

and then it was reacted with phenol

at last

HDP was isolated and purified.The obtained HDP was a kind of white solid

and the yield exceeded 90%.The structure of HDP was characterized by 1H-NMR

31P-NMR and MS.The flame retardance of HDP was discussed

and compared with resorcinol bis(diphenyl phosphate) (HDP) in acrylonitrile-butadiene-styrene (ABS) composites.When HDP or RDP was added into ABS resin with char former Novolac phenol (NP) in the ratio of HDP (RDP)/NP (20/10)

it was very effective in enhancing the LOI value and improving the flame retardation in condensation phase.The thermal degradation properties were was investigated by thermogravimetric analysis (TGA) and cone calorimeter test

and the results showed that the incorporation of HDP or RDP increased its thermal stability and char formation. The smoke suppression of ABS/HDP/NP composites is better than that of ABS/RDP/NP composites.The morphological structures and element distribution of the chars were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).Compared with ABS/RDP/NP composites

the cavities and holes were more uniform

and the distribution phosphorus was more uniform in the char of ABS/HDP/NP composites.The above analysis showed that

when HDP was added to ABS resin with NP

HDP had better flame retardancy in condensation phase than RDP.