Use of Refractory Clay as a Flame Retardant in ABS

This study explores the sustainable use of refractory clay (RC), a low-cost byproduct of the mining industry in southeastern Brazil, as a flame-retardant additive in acrylonitrile-styrene-butadiene (ABS) composites. Composites containing 10 - 20 wt% RC were prepared via twin-screw extrusion and injection molding. Their thermal stability (TGA, DSC), mechanical performance (tensile, flexural, and impact tests), heat deflection temperature (HDT), morphology (SEM), and flammability behavior (UL-94V and UL-94HB) were evaluated. The incorporation of 20 wt% RC significantly enhanced flammability resistance, reducing the linear burning rate to 33.4 mm/min and enabling self-extinguishing behavior under both horizontal and vertical burning tests. These improvements were achieved without compromising the mechanical or thermal properties of ABS. The use of RC presents a sustainable and effective strategy to improve fire safety in polymer systems while adding value to an industrial waste material.