Effects of morphology on mechanical properties of a SBS triblock copolymer

Yamaoka, Ikuro; Kimura, Masao

doi:10.1016/0032-3861(93)90146-2

Cited by 63 publications

(67 citation statements)

References 26 publications

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“…This indicates that the PB lamellae are preferentially deformed followed by void formation, which was also reported by Yamaoka. 27 The deformation behavior observed in sample I is summarized schematically in Figure 3.…”

Section: Micromechanical Deformation Mechanismmentioning

confidence: 98%

Morphology and micromechanical deformation behavior of styrene/butadiene‐block copolymers. I. Toughening mechanisms in asymmetric star block copolymers

Michler

Adhikari

Lebek

et al. 2002

J of Applied Polymer Sci

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Lamellae-forming styrene/butadiene star block copolymers are studied to investigate the influence of morphology on micromechanical deformation mechanisms and mechanical properties by using transmission electron microscopy and tensile testing. A large homogeneous plastic deformation of polystyrene (PS) lamellae is found in styrene/butadiene star block copolymers on the basis of the new mechanism called thin-layer yielding. This mechanism depends strongly on the thickness of the PS lamellae. At a critical thickness of PS lamellae of about 20 nm, a transition from thin-layer yielding mechanism to a crazelike deformation was observed. These new deformation zones are similar to crazes with respect to their propagation perpendicular to direction of external stress and similar to shear bands with respect to an internal shear deformation component of the lamellae in the deformation zones. As a result of our investigations, the mechanical properties of star block copolymers can be understood in correlation with morphology and micromechanical deformation mechanisms.

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Section: Micromechanical Deformation Mechanismmentioning

confidence: 98%

Morphology and micromechanical deformation behavior of styrene/butadiene‐block copolymers. I. Toughening mechanisms in asymmetric star block copolymers

Michler

Adhikari

Lebek

et al. 2002

J of Applied Polymer Sci

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“…The influence of composition and processing on the Izod impact strength of a blend of a ductile styrene-butadiene-styrene (SBS) triblock copolymer and a brittle methyl methacrylate-styrene copolymer has been described by Yamaoka. [1] Our previous investigations have dealt with fracture mechanics properties of binary blends of styrene-butadiene (SB) block copolymers and SB copolymer/polystyrene (PS) blends. [2] Wang and co-workers [3] investigated the crack tearing behaviour of thermoplastic elastomer-like SBS block copolymers as a function of processing and test conditions.…”

Section: Introductionmentioning

confidence: 99%

Influence of Domain Size on Toughness of Poly(styrene‐block‐butadiene) Star Block Copolymer/Polystyrene Blends

Lach

Weidisch

Janke

et al. 2004

Macromol. Rapid Commun.

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Summary: The toughness of poly(styrene‐block‐butadiene) star block copolymer/polystyrene (PS) blends have been investigated using the essential‐work‐of‐fracture approach. The blends show a co‐continuous or layer‐like structure of polystyrene‐rich and polybutadiene‐rich domains arising from the used extrusion process. A tough‐to‐brittle transition at a critical domain size of polystyrene‐rich domains of about 50 nm and a maximum in the non‐essential work of fracture at 20–30% PS (co‐continuous morphology) have been found.

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“…[5,[10][11][12] Styrene-based triblock copolymers with asymmetric styrene end blocks are desirable for enhanced toughness and processability. [12] There is much theoretical [13,[15][16][17][18] and experimental evidence [5,6,12,14,19,20] confirming a significant shift in the block copolymer phase diagram introduced by architectural modification. Morphological deviation (and hence a deviation in the mechanical properties and deformation mechanisms) is introduced by asymmetric architecture, tapered or broad transition, and nonlinear topologies.…”

Section: Introductionmentioning

confidence: 99%

Correlation between Molecular Architecture, Morphology, and Deformation Behaviour of Styrene/Butadiene Block Copolymers

Adhikari

Michler

Huy

et al. 2003

Macro Chemistry & Physics

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The correlation between the molecular architecture, morphology, and micromechanical deformation behaviour of styrene/butadiene (SB) block copolymers with different architectures (linear and star block copolymers, total styrene content, ΦST = 0.74) was studied using dynamic mechanical analysis (DMA), uniaxial tensile testing, scanning force microscopy (SFM), and high voltage electron microscopy (HVEM). Deformation of the individual phases under uniaxial strain at the molecular level was monitored by Fourier transform infrared (FT‐IR) spectroscopy. It was demonstrated that the morphology and deformation behaviour of these block copolymers are strongly influenced by their molecular topology, block symmetry, and the nature of the interface between the component blocks. While the cylindrical morphology (hexagonal polybutadiene (PB) cylinders in polystyrene (PS) matrix) was observed in a symmetric SBS triblock copolymer with ΦST = 0.74, a “two‐component three‐phase” morphology was found in an asymmetric star block copolymer having an equivalent chemical composition and an SBS arm structure. Likewise, an SBS triblock copolymer with a composition identical to the former ones but with highly asymmetric PS end blocks revealed a lamellar morphology. While no locally confined deformation zones were observed in the lamellar block copolymers, the cylindrical block copolymer was found to deform through the formation of highly localised craze‐like deformation zones.

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Effects of morphology on mechanical properties of a SBS triblock copolymer

Cited by 63 publications

References 26 publications

Morphology and micromechanical deformation behavior of styrene/butadiene‐block copolymers. I. Toughening mechanisms in asymmetric star block copolymers

Morphology and micromechanical deformation behavior of styrene/butadiene‐block copolymers. I. Toughening mechanisms in asymmetric star block copolymers

Influence of Domain Size on Toughness of Poly(styrene‐block‐butadiene) Star Block Copolymer/Polystyrene Blends

Correlation between Molecular Architecture, Morphology, and Deformation Behaviour of Styrene/Butadiene Block Copolymers

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