Phase morphologies and mechanical properties of high‐impact polystyrene (HIPS) and polycarbonate blends compatibilized with polystyrene and polyarylate block copolymer

Abstract

Phase morphology and mechanical properties of blends of high-impact polystyrene (HIPS) and polycarbonate (PC) blends compatibilized with a polystyrene (PS) and polyarylate (PAr) (PS-PAr) block copolymer were investigated. Over a broad range of composition from 50/50 through 30/70, HIPS/PC blends formed cocontinuous structures induced by the flow during the extrusion or injection-molding processes. These cocontinuous phases had heterogeneity between the parallel and perpendicular directions to the flow. The micromorphology in the parallel direction to the flow consisted of stringlike phases, which were highly elongated along the flow. Their longitudinal size was long enough to be longer than 180 m, while their lateral size was shorter than 5 m, whereas that in the perpendicular direction to the flow showed a cocontinuous phase with regular spacing due to interconnection or blanching among the stringlike phases. The PS-PAr block copolymer was found to successfully compatibilize the HIPS/PC blends. The lateral size of the stringlike phases could be controlled both by the amount of the PS-PAr block copolymer added and by the shear rate during the extrusion or injection-molding process without changing their longitudinal size. The HIPS/PC blend compatibilized with 3 wt % of the PS-PAr block copolymer under an average shear rate of 675 s Ϫ1 showed a stringlike phase whose lateral size was reduced almost equal to the rubber particle size in HIPS. The tensile modulus and yield stress of the HIPS/PC blends could be explained by the addition rule of each component, while the elongation at break was almost equal to that of PC. These mechanical properties of the HIPS/PC blends can be explained by a parallel connection model independent of the HIPS and PC phases. On the other hand, the toughness factor of the HIPS/PC blends strongly depended on the lateral size of the stringlike phases and the rubber particle size in the HIPS. It was found that the size of the string phases and the rubber particle should be smaller than 1.0 m to attain a reasonable energy absorbency by blending HIPS and PC.

Effect of reactive compatibilisation on the phase morphology and tensile properties of PA12/PP blends

“…Mekhilef et al 9 have shown that addition of copolymer reduced the interfacial tension and, thereby, stabilized the morphology. Oshishi et al 11 studied the phase morphology and mechanical properties of polymer blends the in presence of a block copolymer as compatibiliser and found that the copolymer successfully compatibilized the blends. It has been suggested that the compatibilising efficiency of block copolymer is influenced by several factors such as chemical composition, number of blocks, and the related molecular characteristics.…”

“…[1][2][3][4][5] It has been reported that compatibiliser locates at the interface and suppresses coalescence by stabilizing the interface. 6 Compatibilisation is generally accomplished by adding presynthesized copolymers [7][8][9][10][11][12] or through reactive processing. In the former case, it is important that the copolymer stays at the interface, without dissolving in either of the two polymers or forming mesophase of micelle structure.…”

Mechanical properties of photoaged in situ polymerized PS/EPDM blends

“…The incorporation of dispersed elastomeric particles in a rigid polymer matrix has attracted significant attention because of its industrial importance. [1][2][3] High impact polystyrene (HIPS) is one of the most important toughened commercial systems in which the brittle polystyrene (PS) becomes more ductile. 4,5 However, aging is a serious problem for HIPS and for other rubber-toughened plastics, especially those based on polybutadiene (PB).…”

Wide-angle X-ray diffraction investigation on crystallization behavior of PA6/PS/SEBS-g-MA blends

“…Many researchers have studied the mechanical properties [1,2] and electrical conductivity [3,4] of the co-continuous blends, and have found that the structure presents not only the properties of the components, but also other properties which the components do not possess [5]. Polyamide 6 (PA6) is one of the most important engineering plastics, but its poor dimensional stability and poor impact strength at low temperature have limited its applications.…”