Cage Nanofillers’ Influence on Fire Hazard and Toxic Gases Emitted during Thermal Decomposition of Polyurethane Foam

Polyurethane (PUR), as an engineering polymer, is widely used in many sectors of industries. However, the high fire risks associated with PUR, including the smoke density, a high heat release rate, and the toxicity of combustion products limit its applications in many fields. This paper presents the influence of silsesquioxane fillers, alone and in a synergistic system with halogen-free flame-retardant compounds, on reducing the fire hazard of polyurethane foams. The flammability of PUR composites was determined with the use of a pyrolysis combustion flow calorimeter (PCFC) and a cone calorimeter. The flammability results were supplemented with smoke emission values obtained with the use of a smoke density chamber (SDC) and toxicometric indexes. Toxicometric indexes were determined with the use of an innovative method consisting of a thermo-balance connected to a gas analyzer with the use of a heated transfer line. The obtained test results clearly indicate that the used silsesquioxane compounds, especially in combination with organic phosphorus compounds, reduced the fire risk, as expressed by parameters such as the maximum heat release rate (HRRmax), the total heat release rate (THR), and the maximum smoke density (SDmax). The flame-retardant non-halogen system also reduced the amounts of toxic gases emitted during the decomposition of PUR, especially NOx, HCN, NH3, CO and CO2. According to the literature review, complex studies on the fire hazard of a system of POSS–phosphorus compounds in the PUR matrix have not been published yet. This article presents the complex results of studies, indicating that the POSS–phosphorous compound system can be treated as an alternative to toxic halogen flame-retardant compounds in order to decrease the fire hazard of PUR foam

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.Flammability and smoke density of studied composites were determined in accordance with European standards with the use of cone calorimeter and smoke density chamber.PCDD/F and PAH were determined with the use of GC-MS-MS technique. Toxicometric index was determined with the use of FB-FTIR technique (fluidised bed reactor and the infrared spectrum analysis)