Controllable Synthesis of Submicrometer Core–Shell Modifier and Its Effect on Toughening Polypheylene Ether/Polystyrene Blends

Abstract Core–shell polybutadiene‐graft‐polystyrene (PB‐g‐PS) graft copolymers with different ratios of PB to PS are synthesized by emulsion polymerization. Further, the PB‐g‐PS copolymers are blended with polypheylene ether (PPE) and PS to prepare PPE/PS/PB‐g‐PS blends. The effects of PB‐g‐PS copolymer structure and matrix composition on the morphological, mechanical properties, and deformation mechanism of the blends are studied. The results show that the synthesized submicrometer‐sized PB‐g‐PS copolymer has an excellent toughening efficiency, both the copolymer and PS are introduced into PPE resin to produce a ternary blend which is combined with high toughness and processing properties. The optimum toughening effect on PPE/PS matrix is observed at the core–shell weight ratio of 70/30 in PB‐g‐PS copolymer, and the impact strength of the blends increased from 101 to 550 J m −1 . In addition, the dispersion pattern of rubber particles in the matrix gradually changes from uniform dispersion to aggregation as the core–shell ratio of PB‐g‐PS copolymers increases. On the other hand, with the increase of PPE content, the dispersion of rubber particles in PPE/PS matrix is improved, and the deformation mechanism is changed from cracking to a combination of crazing and shear yielding, which can lead to absorb more energy to achieve better toughness.