Toughening of polycarbonate: Effect of particle size and rubber phase contents of the core‐shell impact modifier

Abstract

ABSTRACT:The toughening behavior of polycarbonate modified with core-shell type particles was investigated. The alloys were found to exhibit maximum impact strength upon addition of a modifier with a poly(butyl acrylate) rubbery core of 0.25 m diameter. The incorporation of particles with diameter greater than 0.25 m resulted in decreased impact strength. The influence of rubber phase contents on toughness was also studied. It was observed that the alloys exhibited maximum impact strength upon addition of 4 wt % rubber phase. Further increase in the rubber phase content resulted in reduced impact strength. Fractography of the samples showed that, below 4 wt % rubber phase content, the fracture occurs mainly by internal crazing and, from 4 wt % onward, only by shear deformation. When the effect of dual particle size distribution was analyzed, it was found that there was only a moderate increase in toughness compared with alloys containing monosized particles.

Mechanistic insights on nanosilica self-networking inducing ultra-toughness of rubber-modified polylactide-based materials

“…[1][2][3][4][5] The morphology of a two-phase system usually results to a balance between the breakup and coalescence of the dispersed domains in the flow field. 6 For uncompatibilized blends, the final particle size increases with the dispersed phase concentration because of increased coalescence.…”

Toughening Modification of Poly(lactic acid) via Melt Blending

“…0.7~0.9 µm) for PLA toughening were identified in the PLA/EBA-GMA/EMA-Zn (80/20-x/x, w/w) blends extruded at 240°C, as shown in Figure 10 (13). Likewise, the optimum particle size has also been reported for other thermoplastic matrices containing a variety of rubbers, such as semi-crystalline nylon-6 (PA6: 0.2~0.5 µm) (14-16), amorphous nylon (a-PA: 0.2~0.5 µm) (17), polycarbonate (PC: 0.10~0.25 µm) (18,19), poly(methylene methacrylate) (PMMA: 0.2~0.3 µm) (20)(21)(22), poly(vinyl chloride) (PVC: 0.2 µm) (23), poly(styrene-co-acrylonitrile) (SAN: 0.75 µm) (24), and polystyrene (PS: 0.8~2.5 µm) (7,24). Wu correlated rubber particle diameter with chain structure parameter of the matrix and claimed that the optimum particle size for toughening decreased as the matrix becomes less brittle (7).…”

Core–shell particles of poly(methyl methacrylate)‐block‐poly(n‐butyl acrylate) synthesized via reversible addition–fragmentation chain‐transfer emulsion polymerization and the polymer's application in toughening polycarbonate

“…22 Elastomers such as styrenebutadiene-styrene block copolymer (SBS), 23 acrylonitrilebutadiene-styrene copolymers, [24][25][26] and core-shell structured particles of poly(methyl methacrylate/styrene) (MBS) 21,23,27,28 and PnBA/PMMA 22,29,30 have been used as impact modifiers. 22 Elastomers such as styrenebutadiene-styrene block copolymer (SBS), 23 acrylonitrilebutadiene-styrene copolymers, [24][25][26] and core-shell structured particles of poly(methyl methacrylate/styrene) (MBS) 21,23,27,28 and PnBA/PMMA 22,29,30 have been used as impact modifiers.…”

“…22 Elastomers such as styrenebutadiene-styrene block copolymer (SBS), 23 acrylonitrilebutadiene-styrene copolymers, [24][25][26] and core-shell structured particles of poly(methyl methacrylate/styrene) (MBS) 21,23,27,28 and PnBA/PMMA 22,29,30 have been used as impact modifiers. 22,29,30 The PMMA shells provided rigidity and good compatibility to the PC matrix, 31,32 and the lightly-crosslinked cores retained the integrity of the particle structure in the modified PC. To produce modified PC with a good dispersion of rubber phase and pre-determined rubber phase size under a wide range of process conditions, core-shell particles composed of a PMMA shell and a slightly-crosslinked rubber core, which was synthesized by traditional emulsion polymerization, were applied.…”