{"knowledge_schema": {"broad_category": "Chemistry \u2192 Polymer Science \u2192 Polymerization Techniques", "refinement": "This problem focuses on the specific methods used in the production of high-impact polystyrene (HIPS), particularly the catalyst systems that influence the properties of the final polymer.", "specific_scope": "The question specifically addresses the catalyst system that achieves the desired rubbery phase dispersion in HIPS production.", "goal": "Identify the correct catalyst system that is commonly used in the production of HIPS to ensure optimal dispersion of the rubbery phase."}, "summary": "This question pertains to polymer science, specifically the production techniques for high-impact polystyrene (HIPS). It requires knowledge of various polymerization methods and their associated catalyst systems. The goal is to identify the catalyst that effectively achieves the desired rubbery phase dispersion within the polystyrene matrix. The correct answer is free radical polymerization with benzoyl peroxide, which is commonly used in HIPS production."}