## 1 Introduction  
Polymers are known for relative high flammability, most often accompanied with the production of smoke during combustion. ABS (acrylonitrile-butadiene-styrene) generates heavy smoke and soot with lack of char formation. Consequently, improving the fire-retardant behavior of polymers is of critical importance for specialists. Many authors have combined ABS with different fire retardants [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12] as well as different clays in order to enhance the synergy between the components [13]. One of the most used clays is the organic montmorillonite (OMT) [13]. Several researchers tried to reduce the polymers' combustibility by adding different fire retardants. For example, [PERSON] et al. [14] added multilayer graphene particles in concentrations of up to 5% and noticed a reduction of 30% in the heat release rate of the polycarbonate ABS, while commercially available flame retardants for ABS are halogen and silicon-containing [15]. Nevertheless, the use of halogen containing fire retardants is rare at this moment due to their negative influence on human health and the environment [16; 17; 18]. Later there has been an increase in using montmorillonite due to its excellent compatibility with ABS (acrylonitrile-butadiene-styrene) was noticed by [PERSON] [19]. On the other hand, one can use the organic modified montmorillonite (OMT) obtained by ion exchange between montmorillonite and C\({}_{16}\) in water, according to [PERSON] et al. [20]. [PERSON] et al. [21] developed a mixture between polycarbonate, ABS, and montmorillonite nanocomposites obtained by melt compounding in a twin-screw extruder and noticed an increase in mechanical properties of the ABS. [PERSON] [22] performed a review on flame retarding performance of different materials and concluded that triphenyl phosphate based materials are the most appropriate as fire retardants. However, it is indicated in the literature that the integration of a quite low quantity of nanoclay (organomodified) in the polymer matrix generates a protective layer throughout combustion [23; 24; 25]. In this context, the clay addition on the material surface acts as a shield that restricts the heat transfer into the material, as well as the volatilization of combustible degradation products and oxygen diffusion into the material [22]. Montmorillonite received lately increased attention due to its exclusive nanoscale layered structure and high aspect ratio, thus enhancing the mechanical, thermal and flame-retardant properties [22; 23; 24; 25]. [PERSON] et al. [26] performed an experimental study on fire behavior involving ABS, montmorillonite, and ammonium polyphosphate (APP) as fire retardant by melting at 175 \({}^{\circ}\)C. A change in LOI (limiting oxygen index) values was observed on increasing the OMT content to 2% while on increasing it to higher values the benefits were not obvious. With this idea, the conclusion was that OMT alone cannot effectively enhance the flame retardancy of ABS [26]. Similar studies were conducted by [PERSON] et al. [27], [PERSON] and [PERSON] [28] and [PERSON] et al. [29], who also noticed that there was no noteworthy modification in flame retardancy for the mixtures containing only clays, indicating that another FR (fire retardant) is needed to be added to the material. Multicomponent flame retardant systems containing aluminum diethylphosphonate (AlPi) in thermoplastic styrene-ethylene-butylene-styrene elastomers have been investigated in terms of oxygen index, UL 94, cone calorimeter, and mechanical testing by [PERSON] et al. [30]. The authors found that, by adding the fire retardant, an oxygen index of up to 27 vol% was obtained together with a horizontal burn rating in UL 94 with immediate self-extinction and the peak heat release rate decreased by up to 85%. As a conclusion, such AlPi based multicomponent systems have become a good alternative for fire retardant materials.