Acrylonitrile butadiene styrene (‘ABS’) is a high volume engineering plastic, favoured for its strength, scratch resistance and attractive finish. ABS is produced from three monomers: acrylonitrile (provides thermal and chemical resistance), butadiene (provides rubber-like ductility and impact resistance) and styrene (provides stiffness, the ability to be easily processed and reduces overall cost). ABS resins typically contain at least 50% styrene, with varying proportions of acrylonitrile and butadiene. There are two main processes that can be used to produce ABS: mass and emulsion. In the mass process, styrene and acrylonitrile are mass polymerized in the presence of a rubber substrate (polybutadiene or styrenebutadiene elastomer). In the emulsion process, ABS is prepared by polymerizing butadiene in aqueous emulsion using radical initiators, emulsifiers, followed by a grafting step of emulsion polymerizing styrene and acrylonitrile onto the polybutadiene latex elastomer substrate.
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.