INVESTIGATION OF PHASE MORPHOLOGY, THERMAL-BEHAVIOR, AND IMPACT PROPERTIES OF POLYAMIDE-1010 POLYSTYRENE BLENDS COMPATIBILIZED BY LIGHTLY SULFONATED POLYSTYRENE IONOMERS/

The phase morphology, thermal behavior, and impact properties of polya mide-1010 (PA)/polystyrene (PS) blends compatibilized by sulfonated po lystyrene (HSPS) and their zinc salts (ZnSPS) were investigated, using a dynamic mechanical analyzer (DMA), a scanning electron microscope ( SEM), a differential scanning calorimetry (DSC), and a pendulum impact tester. It was found that the addition of the ionomer had an improved effect on the phase morphology of the resulting blends, where the HSP S was a more effective compatibilizer than was the ZnSPS due to its lo w melt viscosity and less self-agglomeration in the PA matrix. DSC res ults showed that with increasing the ionomer content the amount of the less perfect crystals of PA increased in these blends and, hence, led to a small increase in the crystallinity of the PA phase. The crystal lization rate of the PA in the resulting blends was accelerated slight ly by the ZnSPS but was decreased by the HSPS, which was probably due to the nucleation effect of ZnSPS for PA but no nucleation of HSPS. Th e best improvement in the notched impact strength of the blends was ac hieved with the content of the ionomer up to 20 wt % based on the amou nt of PS. (C) 1998 John Wiley & Sons, Inc.