Polymer blends of polyamide-6 (PA6) and poly(phenylene oxide) (PPO) compatibilized by styrene-maleic anhydride (SMA) copolymer

The commercially available styrene-maleic anhydride copolymer (SMA-8% MA) has been demonstrated to be a highly effective compatibilizer for polymer blends of polyamide-6 (PA6) and poly(2,6-dimethyl-1,4-phenylene oxide) (PPO). SMA is miscible with PPO and tends to be dissolved in the PPO phase during the earlier stages of melt blending. The dissolved SMA has the chance to make contact and reacts with PA6 at the interface to form the desirable SMA-g-PA6 copolymer. This in situ-formed SMA-g-PA6 graft copolymer tends to anchor along the interface to reduce the interfacial tension and results in finer phase domains. The overall mechanical property improvement of the compatibilized blends over the uncompatibilized counterparts is drastic, especially for these PPO-rich blends. The mechanism of this conventional reactive compatibilization system has been discussed in detail. (C) 1997 Elsevier Science Ltd.