Blends of bisphenol A polycarbonate and rubber-toughened styrene-maleic anhydride copolymers

The morphology and mechanical properties of polycarbonate (PC) blends with rubber-toughened styrene-maleic anhydride copolymer materials (TSMA) were investigated and compared with the properties of blends of PC with acrylonitrile-butadiene-styrene (ABS) materials. The PC/TSMA. blends showed similar composition dependence of properties as the comparable PC/ABS blends. Polycarbonate blends with TSMA exhibited higher notched Izod impact toughness than pure PC under sharp-notched conditions but the improvements are somewhat less than observed for similar blends with ABS. Since PC is known for its impact toughness except under sharp-notched conditions, this represents a significant advantage of the rubber-modified blends. PC blends with styrene-maleic anhydride copolymer (SMA) were compared to those with a styrene-acrylonitrile copolymer (SAN). The trends in blend morphology and mechanical properties were found to be qualitatively similar for the two types of copolymers. PC/SMA blends are nearly transparent or slightly pearlescent. (C) 1999 John Wiley & Sons, Inc.