Submicrometer‐sized rubber particles as “craze‐bridge” for toughening polystyrene/high‐impact polystyrene

Abstract

Submicrometer core‐shell polybutadiene‐graft‐polystyrene (PB‐g‐PS) copolymers were synthesized by emulsion grafting polymerization with 1,2‐azobisisobutyronitrile as an initiator. Then, PB‐g‐PS copolymers were blended with high‐impact polystyrene (HIPS) and PS to prepare HIPS/PS/PB‐g‐PS. It is generally accepted that PS could only be toughened by 1–3‐μm rubber particles effectively. From the Izod impact test, however, the results showed that PS could be toughened effectively by submicrometer rubber particles (around 300 nm) in our study. Moreover, the impact strength of HIPS/PS/PB‐g‐PS is much higher than that of HIPS due to the synergism between submicrometer rubber particles and micrometer salami particles. Subsequently, the stress‐whitening zones for HIPS, PS/PB‐g‐PS, and HIPS/PS/PB‐g‐PS were also observed in detail by transmission electron microscope. Based on mechanical properties and deformation morphologies, the deformation mechanism in the HIPS/PS/PB‐g‐PS blends was given as follows: crazes could be initiated from large rubber particles, passed through “craze‐bridge” rubber particles, and ended to neighboring small one, which prevented excessively crazing to be form cracks, absorbed energy, and finally enhanced the toughness of PS. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Fully bio-based, highly toughened and heat-resistant poly(L-lactide) ternary blends via dynamic vulcanization with poly(D-lactide) and unsaturated bioelastomer

“…Therefore, the impact strength of the ternary blends first increases to 312.8 and 327.8 J m −1 with addition of 5 and 10 wt.% PDLA and then decreases to 273.7 and 132.5 J m −1 with PDLA content further increases to 15 and 20 wt.%, respectively. The impact strength of annealed injection molded ternary blends is much smaller than that of regular injection molded counterparts, but the values are several times higher than that of so-called [59]. Therefore, the annealed injection molded fully bio-based ternary blends may have the potential to replace non-sustainable HIPS in many applications from the viewpoint of toughness.…”

Influence of SEBS-MA and SBS compatibilizers on properties and morphology of blends of polystyrene/rubber residue (SBRr) from the footwear industry

“…Although the rubber reduction of this mixture was greater than the one of PS/ SBS + SBRr blend, this system did not present a better result of impact strength since the values obtained were less than the values found for the PS/SBS + SBRr blend (Table 1). The studies by Zhu et al (2013) evidence that there is an upper and lower limit of critical size beyond which the rubber particles are not effective for toughening. According to the authors, particles below a certain limit are unable to cavitate, and thus do not participate of the toughening mechanism.…”

Biodegradable Polylactide‐Based Composites

“…Phase separation induced by immiscible blends has been commonly used for improving fragile commodity polymers as PS and PMMA with a rubber modification leading into HIPS [46] and high impact PMMA [47]. However, the modifications in polylactides with biodegradable polymers as polycaprolactone (PCL) are an efficient way to toughen polylactides [48].…”