Acrylonitrile styrene acrylate (ASA)

Acrylonitrile-styrene-acrylate is the predecessor of ABS (Acrylonitrile- butadiene-styrene). ASA is an acrylate rubber modified styrene acrylonitrile copolymer with an acrylate rubber modifier included at the polymerisation stage. Developed to create similar material as ABS but superior in terms of weather resistance.

Properties

Acrylonitrile styrene acrylate (ASA) has great toughness and rigidity, good chemical resistance and thermal stability, outstanding resistance to weather, aging and yellowing and high gloss.

History

ASA was first introduced to the market by BASF in around 1970 as Luran® S, based on patents from the 1960s (3-6). Developed to create similar material as Acrylonitrile-Butadiene-Styrene (ABS) but superior in terms of weather resistance. ASA polymers are produced by introducing a grafted acrylic ester elastomer during the copolymerization reaction between styrene and acrylonitrile.

Common Application

Because of the enhanced weather resistance, ASA is used extensively in the automotive industries, and further in general for outdoor applications. Asa polymers have been widely applied to glossy coloured outdoor products including;

• Automotive outside parts
• Boats
• Garden furniture
• Household electrical products
• Satellite antennas or
• Street lamps
• Siphonic roof outlets

References

1. http://www.bpf.co.uk/plastipedia/polymers/SAN.aspx

2. Handbook of Engineering and Specialty Thermoplastic, Polyolefins and Styrenics