Acrylonitrile butadiene styrene (ABS)

Acrylonitrile butadiene styrene (ABS) is a two phase polymer blend. A continuous phase of styrene-acrylonitrile copolymer (SAN) gives the materials rigidity, hardness and heat resistance. The toughness of ABS is the result of submicroscopically fine polybutadiene rubber particles uniformly distributed in the SAN matrix.

Properties

ABS is readily modified both by the addition of additives and by variation of the ratio of the three monomers Acrylonitrile, Butadiene and Styrene: hence grades available include high and medium impact, high heat resistance, and electroplatable. Fibre reinforcement can be incorporated to increase stiffness and dimensional stability. ABS is readily blended or alloyed with other polymers further increasing the range of properties available. Fire retardancy may be obtained either by the inclusion of fire retardant additives or by blending with PVC. The natural material is an opaque ivory colour and is readily coloured with pigments or dyes. Transparent grades are also available.

A variety of grades are available for different applications, the material is typically injection moulded or extruded.

History

Styrene Acrylonitrile copolymers have been available since the 1940’s and while its increased toughness over styrene made it suitable for many applications, its limitations led to the introduction of a rubber (butadiene) as a third monomer and hence was born the range of materials popularly referred to as ABS plastics. These became available in the 1950’s and the variability of these copolymers and ease of processing has led to ABS becoming the most popular of the engineering polymers.

Common Applications

ABS, a hard, tough, heat-resistant engineering plastic that is widely used in appliance housings, luggage, pipe fittings, and automotive interior parts. Essentially a styrene-acrylonitrile copolymer modified by butadiene rubber, ABS combines the resilience of polybutadiene with the hardness and rigidity of polyacrylonitrile and polystyrene. ABS was patented in 1948 and introduced to commercial markets by the Borg-Warner Corporation in 1954.

Reference

1. http://www.bpf.co.uk/plastipedia/polymers/ABS_and_Other_Specialist_Styrenics.aspx 2. https://global.britannica.com/science/acrylonitrile-butadiene-styrene-copolymer 3. https://plastics.ulprospector.com/generics/1/c/t/acrylonitrile-butadiene-styrene-abs-properties-processing