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-phenylen e oxide) (PPO). SMA is miscible with PPO and tends to be dissolved in the PPO phase during the earlier stages of melt blending. The dissolve d SMA has the chance to make contact and reacts with PA6 at the interf ace 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 t he 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-ri ch blends. The mechanism of this conventional reactive compatibilizati on system has been discussed in detail. (C) 1997 Elsevier Science Ltd.