Development of Halogen‐Free Flame Retardant Acrylonitrile Butadiene Styrene (ABS) Based Composite Materials

Abstract Natural flammability properties of acrylonitrile butadiene styrene (ABS) seriously limit the use of ABS polymers in industries. Improving the flammability performance of ABS by using halogenated additives has been a very common method in the past. However, with increasing environmental awareness, the use of halogen‐containing additives has been severely limited over time. Therefore, we aimed to use halogen‐free flame‐retardant additives in our study to improve the flame‐retardant properties of ABS. ABS‐based composites containing 20, 25, 30 % aluminum diethyl‐phosphinate (AlPi) and ammonium polyphosphate (APP) halogen‐free flame‐retardant additives by weight, were prepared using a twin‐screw extruder. V0 rating according to UL 94 standard for the thickness of 1.5 mm, limiting oxygen index (LOI) value higher than 28 %, and glow wire flammability index of 960 °C were aimed in this study. To improve the LOI values of flame‐retardant ABS composites, pentaerythritol (PER), zinc borate (ZB), and magnesium hydroxide were used. The highest LOI value was obtained to be 28.1 % by using 12.5 wt.% AlPi, 12.5 wt.% APP, 5 wt.% PER and 3 wt.% ZB. The effect of flame retardants on mechanical properties (flexural and tensile properties), impact properties (Izod and Charpy‐notched impact strength), thermal properties, melt flow index, and morphology (scanning electron microscopy) of ABS were also examined.