Thermal behaviors and flame retardancy of novel flame‐retardant, oil‐filled styrene–ethylene–butadiene–styrene block copolymer–polypropylene materials.

A novel halogen‐free flame‐retardant material consisting of a novel cyclotriphosphazene‐based char‐forming agent, aluminum diethyl phosphinate, nickel trioxide (Ni2O3), an oil‐filled styrene–ethylene–butadiene–styrene block copolymer, and polypropylene was studied. On the basis of their UL‐94 ratings and limiting oxygen index (LOI) data, the flame retardants exhibited very effective flame‐retardant properties in the material. When the loading of flame retardant (FR) was only 35 wt %, the flame‐retardant material attained a UL‐94 V‐0 (1.6 mm) rating, and its LOI value reached 31%. The thermogravimetric analysis data indicated that the flame retardant effectively reduced the peak mass loss because of the formation of abundant char residue. Moreover, the flammability parameters of the material obtained from UL‐94, LOI, and cone calorimetry tests demonstrated that the fire safety performance of the material with Ni2O3 obviously improved. The morphological structure of the char residue of the material with the flame retardant and Ni2O3 showed a dense and continuous carbon layer. The high‐quality carbon layer formed on the surface of the polymer material matrix showed a heat‐insulating effect. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46888. [ABSTRACT FROM AUTHOR]