Polystyrene is one of the oldest industrial thermoplastic polymers, which has a wide range of applications. This bright, pure amorphous plastic has the advantages of easy processing, rigidity, dimensional stability and transparency, but its low impact strength limits its application.High impact polystyrene is a small amount of polybutadiene connected to the polystyrene matrix.

There are two basic processes for HIPS production: intermittent process and continuous process. The two processes generally use prepolymerization first. After the completion of prepolymerization, the polymerization is continued in the form of suspension in the intermittent process and in the form of solution in the continuous process. Therefore, intermittent process is also called bulk suspension process, and continuous process is also called solution process.