Co-toughened Polystyrene by Submicrometer-Sized Core–Shell Rubber Particles and Micrometer-Sized Salami Rubber Particles

Abstract

A series of submicrometer-sized polybutadiene (PB) rubber particles with different diameters ranging from 100 to 450 nm were prepared via an emulsion polymerization. Subsequently, core–shell polybutadiene-graft-polystyrene (PB-g-PS) particles were synthesized using a redox initiator system (cumene hydroperoxide and ferrous sulfate) by an emulsion grafting polymerization. Then the submicrometer sized PB-g-PS impact modifiers were utilized to toughen polystyrene (PS) by blending PS and high-impact polystyrene. From measuring mechanical properties, it was found that the notched impact strength of toughened PS was significantly influenced by core–shell PB-g-PS particle size. When the rubber particle size was above 300 nm, the notched impact strength was 208 J/m, nearly 2 times than that of toughened PS with particle size 100 nm. Moreover, the stress whitening zones were observed by transmission electron microscopy, and the result showed that multiple crazing is its dominative toughening mechanism.

Influence of the structure of sub‐micrometer core‐shell rubber particles and matrix composition on the mechanical properties, morphological structure and deformation mechanism of rubber‐modified polyphenylene oxide/polystyrene blends

“…The PB‐g‐PS graft copolymers with core‐shell ratio (PB/PS) from 30/70 (wt/wt) to 80/20 (wt/wt) was synthesized by emulsion polymerization using redox initiation system of cumene hydroperoxide ferrous sulfate (CHP‐FeSO 4 ) 35 . Previous studies found that the best toughening effect of PB‐g‐PS graft copolymers was achieved when the size of PB rubber particles was 300 nm 38 . Therefore, in this work, PBL with particle size of 300 nm was chosen as the core layer of PB‐g‐PS graft copolymer.…”

“…After the butanone solution of the dried PB‐g‐PS graft copolymer was shaken at room temperature for 24 h, the solution was centrifuged at 10,000 rpm in a GL‐21M centrifugal machine for 30 min with a temperature of 0°C. The GD and GE were calculated using the following equations 38 : where Gel% is the weight fraction of the precipitate insoluble in butanone, PB% is the weight fraction of the rubber phase of the PB‐g‐PS graft copolymer.…”

“…35 Previous studies found that the best toughening effect of PB-g-PS graft copolymers was achieved when the size of PB rubber particles was 300 nm. 38 Therefore, in this work, PBL with particle size of 300 nm was chosen as the core layer of PB-g-PS graft copolymer. In the process of graft polymerization, styrene (St) was grafted on PB latex particles.…”

Effect of polypropylene molecular weight distribution on the balance between the toughness and rigidity of the impact polypropylene composites

“…Many thermoplastic polymers such as polypropylene (PP), 1–9 polylactide (PLA), 10–18 polystyrene (PS), 19,20 and polyamide 6 (PA6), 21–25 and so on, are with poor impact resistance. This drawback can be generally improved by compositing rubber or elastomer in both experiment and industry.…”

Effect of Entanglement Density on Mechanical Properties and Deformation Behavior of Rubber-Modified PVC/α-MSAN Blends

“…It can introduce extensive plastic deformation into the fracture process of the material, thereby increasing the toughness of polymers effectively. Numerous rubber-modified polymer blends and composite systems have been developed to improve the toughness. − Three kinds of toughening mechanisms, crazing, interfacial cavitation between the rubber particles and the matrix or the internal cavitation within the rubber particles, and shear yielding, have been found in rubber-toughened polymeric materials.…”