The effect of the lignocellulosic filler on the reduction of fire hazard of styrene-butadiene rubber composites, including the reduction of smoke, PCDD/F, PAH emissions and toxicity during its thermal decomposition

Carbon black commonly found in elastomeric composites is the main precursor of smoke formed during thermal decomposition and combustion of these materials. It has been proven that soot particles suspended in the air, absorbing carcinogenic, mutagenic and teratogenic, organic compounds from the groups of dioxins, furans and polyaromatic hydrocarbons, penetrating into living organisms through the respiratory tract, pose a serious threat to human health and life. Therefore, it has been proved in this paper, that partial replacement of carbon black with a natural lignocellulosic filler, also in synergetic system with non-halogen flame retardants, not only reduces the flammability of the obtained composites, but also significantly reduces their smoke formation, PCDD/Fs and PAHs emissions, as well as the toxicity of gaseous inorganic decomposition products expressed by a toxicometric index taking into account the emissions of CO, CO2, SO2, NO2, HCl and HCN. In addition, the use of natural fillers in elastomeric composites perfectly fits the European regulations regarding the development of reusable or recyclable materials and reducing the cost of their production through the use of cheap renewable raw materials.