Polycarbonate–acrylonitrile-butadiene-styrene blends with simultaneously improved compatibility and flame retardancy

Tri(2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-1-oxo-4-hydroxymethyl) phenylsilane (TPPSi) was employed as a flame retardant and polydimethylsiloxane-g-styrene-g-methyl methacrylate copolymer (PSM) as a compatibilizer in polycarbonate–acrylonitrile-butadiene-styrene (PC–ABS) blends. The effect of TPPSi and PSM on the flame retardancy and compatibilization of PC–ABS was investigated by UL-94 vertical burning tests, DMA and SEM. The results indicated that the PC–ABS blend with 8 wt% TPPSi and 5 wt% PSM possessed both high flame retardancy and impact strength. It was found that PSM played an effective compatibilization role in the PC–ABS–TPPSi blend and elevated the thermal stability of the blend. A synergistic flame-retardant mechanism between phosphorus and silicon was presented by TGA, SEM/EDX analysis, FT-IR and Raman spectra of the residue.