Styrene monomer (‘SM’) is an important intermediate material used in the production of a variety of plastic and synthetic rubber products with key applications in the electronics, healthcare, household, automotive, construction and packaging sectors. Styrene is a liquid hydrocarbon produced from ethylene and benzene, using either the ethylbenzene dehydrogenation (‘EBSM’) process or the propylene oxide styrene monomer (‘POSM’) process. SM is primarily used as feedstock in PS, ABS and Specialties product manufacturing.
Polystyrene is a thermoplastic resin obtained from the polymerization of SM. Due to its easy processability, PS has many applications, including construction, electronics, household appliances, toys, disposables and packaging (see table below for examples of key applications). There are two basic types of PS: (i) crystal PS (straight, or general purpose PS (‘GPPS’)) and (ii) high impact PS (‘HIPS’). GPPS is used in sectors like food packaging, while HIPS is a more durable plastic used in household appliances such as refrigerators.
Acrylonitrile butadiene styrene (‘ABS’) is a high volume engineering plastic, favoured for its strength, scratch resistance and attractive finish. Traditionally, ABS producers would offer customers numerous grades and colour options. Today, following the emergence of very large plants and production lines in the industry, most ABS producers focus production on either (i) standard ABS, which is uncoloured, (ABS Standard) or (ii) pre-coloured ABS (ABS Specialty). ABS resin is made into a wide range of components via injection moulding and extrusion. Primary uses are in the production of automotive parts, consumer electronics and household appliances.
Specialties consist of ABS Specialties, such as high heat resistance ABS and pre-coloured ABS, and copolymers such as styrene-acrylonitrile (‘SAN’), acrylonitrile styrene acrylate (‘ASA’), methyl methacrylate acrylonitrile butadiene styrene (‘MABS’) and SAN styrene butadiene block copolymers (‘SBCs’). SAN is a rigid and transparent polymer made from styrene and acrylonitrile. SAN is one component in the production of ABS. In addition, SAN has some commercial end uses as a transparent polymer in its own right, including in kitchenware, computer products, battery cases, ballpoint pens and packaging material. ASA is a styrene derivative produced by introducing a grafted acrylic ester elastomer (elastic polymer) in a polymer matrix consisting of SAN. ASA is suitable for injection moulding, extrusion, blow moulding and thermoforming. End uses include automotive components, construction, telecoms, household appliances and sports and leisure equipment. MABS is a tough, transparent plastic, with high brilliance and surface finish. It exhibits good chemical resistance, good tensile strength and stiffness and is easy to process, print on, sterilize and bond with other resins. MABS is used in applications including medical technology and diagnostics, cosmetics and hygiene. SBCs are a class of block copolymers of styrene and butadiene produced either as an elastomer or as a rigid product. Rigid products have a high transparency and are often used to toughen GPPS. These products exhibit high surface gloss, rigidity and toughness, they can be printed and they can be compounded with other materials. SBCs as elastomers have high-performance abrasion resistance and are frequently used for injection moulded parts as a hot-melt adhesive or as additives to improve the properties of bitumen.