Effect of Elastomer Level and Resin Molecular Weight On Properties and Weatherability of Olefin Modified Styrene-Acrylonitrile

Olefin modified styrene-acrylonitrile (OSA) polymers are high impact thermo plastics designed for resistance to changes in mechanical properties and ap pearance when exposed outdoors. The effects of changes in elastomer level and SAN molecular weight on initial properties and retention of toughness during weathering were studied for a series of OSA blends. Specimens were exposed in Miami, Florida and in a fluorescent sunlamp/blacklight device. Changes in mechanical properties were tracked by means of a chip impact test. Changes in surface morphology were also monitored.