Effects of reactive functional groups in the compatibilizer on mechanical properties of compatibilized blends

The compatibility of blends of polyamide‐6/[styrene‐(ethylene‐butylene)‐styrene] triblock copolymer (SEBS) was enhanced with a compatibilizer, maleated SEBS, whose compositions were varied from 0 to 4 wt % of the blends. The maleated SEBS (MA‐g‐SEBS) was synthesized by reacting (grafting) maleic anhydride (MA) with SEBS in the laboratory at various maleic anhydride concentrations ranging from 8 to 13 wt % of the maleated compatibilizer. The effects of graft levels of the reactive MA functional group in the compatibilizer on the effectiveness in compatibilizing the blends were investigated. The morphology and the impact strengths of the compatibilized blends were determined. It was found that, depending on the maleated extents, the compatibilizer influenced significantly the properties of the blends. Although the maleated extents (graft ratios) of the compatibilizer is influential, the concentrations of the compatibilizer in the blends more sensitively affected the mechanical properties of the compatibilized blends. In summary, this study has shown that by increasing the MA contents (within the reported window) in the compatibilizer, the impact toughness could be more dramatically improved. © 1994 John Wiley & Sons, Inc.