The effect of different flame retardant compound ratios on the fire resistance of rubber foams

Acrylonitrile butadiene rubber (NBR) foam, commonly used for insulation in buildings, is highly flammable due to its chemical structure. It is frequently used in structures with large numbers of people, such as schools, hospitals, trains, and shopping malls, for energy-saving purposes. Research has shown with statistical data that the majority of deaths during fires are not caused by burning but by poisoning due to toxic gases produced during the fire. The aim of this study is to increase the fire resistance of rubber foams used in buildings and to reduce smoke formation during a fire. In the industry, halogenated flame retardants are commonly used for fire resistance due to their low cost, effectiveness even in small quantities, and easy availability. However, halogenated flame retardants have highly detrimental effects on human health and the environment. Therefore, in this study, halogen-free flame retardants such as aluminum trihydrate (ATH) and ammonium polyphosphate (APP) were used. In addition to 195 phr (parts per hundred rubber) of ATH, 20 and 40 phr of APP from Exolit AP 422 and 20 phr of APP from Exolit AP 760 were added. The samples were subjected to LOI (Limited Oxygen Index), TGA (Thermogravimetric Analysis), and cone calorimeter tests, and the results were evaluated.