Blends of syndiotactic polystyrene with SEBS triblock copolymers

Abstract

Blending of styrene-b-(ethylene-co-1-butene)-b-styrene (SEBS) triblock copolymers with syndiotactic polystyrene (PSsyn) has been performed in a Brabender mixer above the higher glass transition temperature of the triblock copolymer but below the PSsyn melting point. The large excess of the triblock copolymer over the homopolymer as well as the signi®cant amount of plasticized amorphous PSsyn phase allowed the easy processing under the used temperature conditions with good interface compatibility. The consequent interfacial adhesion between the amorphous PS phase and the unmelted PSsyn crystallites affects both the ®nal morphology of the blend as well as its dynamic behavior. Indeed, such solid particles act as reinforcing point of the overall blend structure, as evidenced by scanning electron microscopy. Moreover, they contribute to a T g increase in the order of 20 8C with respect to pure SEBS and to an appreciable conservation of mechanical properties at temperatures higher than the T g of the PS blocks of SEBS. The mechanical and thermal behavior of the synthesized blends has been studied and tentatively correlated to the molecular weight ratio between PSsyn and the PS blocks of SEBS. q

The effect of poly[styrene-b-(ethylene-co-butylene)-b-styrene] on dielectric, thermal, and morphological characteristics of polypropylene/silica nanocomposites

“…The endothermic event with a temperature peak of ∼17.5°C and around 3 J/g heat flow can be ascribed to locally ordered EB domains. Although there are only few attempts to determine T g for SEBS blocks by DSC, our results are very close to already reported T g values determined by DSC and other techniques . Glass transition for SEBS blocks in nanocomposites could not be detected by DSC probably because of the small concentration of SEBS (≤10 wt%) in these composites.…”

In situ thermal reduction of graphene oxide in a styrene-ethylene/butylene-styrene triblock copolymer via melt blending

“…PS is a brittle polymer and toughening modification is often performed to improve the toughness of PS before practical application. SEBS is a common modifier in toughening PS and it is partially miscible with PS . Graphene has been widely reported to efficiently improve the mechanical properties of polymers .…”

Thermal & morphological evaluation of linear and radial SEBS- polypropylene blends

“…In some cases cryogenic fracture surface is an efficient method to evaluate interactions between phases in blends [18,19] . Several studies of SEBS-polyolefinic blends report a phase separation between olefinic and elastomeric phases, when PP is in higher amount [17,20,21] . In case of radial SEBS-PP blends ( Figure 5) the morphology is quite different due to the presence of channels, rough areas and some SEBS pieces that are not dispersed on the PP matrix, mainly attributed to radial structure of elastomer that not allows good dispersion between phases.…”