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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. [ABSTRACT FROM AUTHOR]

Polyamide 4.6 has excellent properties, such as high temperature resistance, crystallinity, fatigue resistance, melting temperature, excellent creep resistance, toughness, and good wear properties, but low thermal conductivity values. For this reason, its use in thermal applications has been limited. In this study, its use in thermal applications can be increased by increasing its thermal conductivity with carbon‐based fillers and reinforcements added to the PA46 structure. The aim of this study is to examine the carbon fiber (CF), synthetic graphite (SG) and graphene nanoplatelet (G) loading on the mechanical, thermal, physical, and electrical properties of polyamide 4.6, which are produced using co‐ rotating twin‐screw extrusion. Tensile and flexural strength of polyamide 4.6 increased with the addition of CF at all weight fractions. The highest electrical conductivity value was measured as 4.01 S/cm in PA46‐20CF‐20SG‐3G composite material. The highest in‐plane thermal conductivity achieved in this study at 20 wt% CF, 20 wt% synthetic graphite, and 5 wt% graphene loading was 20.43 W/mK. However, the highest through‐plane thermal conductivity value was obtained to be 4.19 W/mK at 20 wt% CF. Graphene and synthetic graphite are more efficient to increase the in‐plane thermal conductivity, while CF is more efficient to increase the through‐plane thermal conductivity. [ABSTRACT FROM AUTHOR]