Polystyrene and styrene copolymers. I. Their manufacture and application

The manufacturing processes for polystyrene (PS) and its copolymers, including styrene–acrylonitrile (SAN), high impact polystyrene (HIPS), acrylonitrile–butadiene–styrene (ABS), styrene–butadiene latex (SBR for coating), styrene–butadiene block copolymers (SBS), and styrene–acrylate copolymers (SMMA), are discussed and illustrated. The synthetic methods for such products are bulk, emulsion, suspension, and free radical polymerization techniques, all either in batch or in continuous operations. By comparison, it was found that continuous bulk is the most economical process among the above‐mentioned polymerization methods. However, the suspension method is still the only way to make expandable polystyrene beads (EPS). Some ionic polymerization techniques for making homo‐ and copolymers are also discussed. Types of styrene‐containing polymers, like all other resins, are classified according to their property distribution. Some are uniquely outstanding and others have a balance of properties, which, in turn, are functions of the molecular weight and molecular weight distribution (MWD), the nature of the components, and the methods and conditions of polymerization. Therefore, each product can be produced in many grades, for a variety of applications.