Polystyrene is a polymer widely used in the production of cabinets, housings, furniture, packing boxes, and food packaging material. It has a high molecular weight and can be used as homo- and co-polymers, thermoplastic elastomers, and foamed polystyrene (EPS). Gel Permeation Chromatography (GPC) is used to evaluate the molecular weight of each batch of produced polymer to ensure the highest quality.