From incompatible poly(aryl ether sulfone)/polyamide 4.6. blends to new impact resistant alloys by a synergistic combination of a block copolymer emulsifier and an impact modifier

The compatibilization and impact modification of blends of a relatively new engineering plastic polyamide 4.6 (PA 4.6) and a poly(aryl ether sulfone) (PSU) are investigated. PSU-b-PA6 block copolymers, which can be easily synthesized by ring opening polymerization of ϵ-caprolactam in the presence of a commercial PSU, were found to be very efficient emulsifiers for these incompatible blends. Small amounts (1–4%) of copolymer are sufficient to significantly reduce the particle size and to improve the tensile and impact properties. Combinations of the copolymer and an impact modifier (ethylene-propylene rubber grafted with maleic anhydride) are synergistic and high impact PSU/PA 4.6 alloys are obtained in that way.