From flame retardant polystyrene foams to intrinsically flame retardant styrenic copolymers without halogens

A combination of organo‐phosphorus flame retardants and organic disulfides proved to provide an efficient, completely halogen‐free flame retardant solution for polystyrene foams and impact‐modified polystyrene (HIPS). Elucidation of the underlying flame retardant mechanisms enabled the design and synthesis of a novel set of intrinsically flame retardant styrenic copolymers without halogens in a flexible building‐block approach using elemental sulfur and phosphorous(meth)acrylates as comonomers.