Molecular architectures of four‐arm star‐shaped styrene‐butadiene copolymer

Zhang, Lina; Ma, Zhaocheng; Xiong, Xiaopeng; Xu, Xiaojuan; Ma, Rui; Li, Yang

doi:10.1002/app.21533

Cited by 3 publications

(2 citation statements)

References 18 publications

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“…The weight percentages of each fraction, the weight-average molecular weight (M w ), polydispersity indices (d), and [] for the samples are summarized in Table I. 802-F1, 802-F2, and 802-F3 were composed mainly of four arms, two arms, and one arm, respectively, 20 and their molecular structures are schemed in Figure 2. There is no three-arm SBS fraction detected in the samples.…”

Section: Measurement Of Propertiesmentioning

confidence: 99%

Effects of molecular weight and arm number on properties of star‐shape styrene–butadiene–styrene triblock copolymer

Xiong

Zhang

et al. 2004

J of Applied Polymer Sci

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A star-shape styrene-butadiene-styrene triblock copolymer SBS (802) was synthesized and fractionated into four fractions coded as 802-F1 (four arms), 802-F2 (two arms), 802-F3 (one arm), and 802-F4 by repeating fractional precipitation. Their weight-average molecular weight (M w ) was measured by size-exclusion chromatography combined with laser light scattering to be 16.0 ϫ 10 4 , 8.2 ϫ 10 4 , 4.3 ϫ 10 4 , and 1.19 ϫ 10 4 , respectively. The samples were, respectively, compressionmolded and solution-cast to obtain the sheets coded as 802C, 802-F1C, 802-F2C, and 802S, 802-F1S, 802-F2S. The structures and mechanical properties of the sheets were characterized by 1 H-NMR, scanning electron microscope, wide-angle X-ray diffractometer, tensile testing, and dynamic mechanical thermal analysis. The results indicated that the compression-molded 802-F1C exhibited the higher tensile strength ( b, 28.4 MPa) and elongation at break ( b , 1610%), and its optical transmittance is much higher than those of 802C and 802-F2C. This work revealed that the star-shape SBS with four arms could be helpful in the enhancement of the properties as a result of good miscibility of the compression-molded SBS sheets.

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Section: Measurement Of Propertiesmentioning

confidence: 99%

Effects of molecular weight and arm number on properties of star‐shape styrene–butadiene–styrene triblock copolymer

Xiong

Zhang

et al. 2004

J of Applied Polymer Sci

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“…It is well known that styrene–butadiene block copolymers (SBS) constitute an important class of thermoplastic elastomers 11–13. It is worth noting that the application of SBS and its composites greatly depends on their physical properties, which are decided by their molecular structure 14–20. Compared with linear SBS, the star‐shaped SBS has a more compact morphology, a reduced bulk and solution viscosity, and the better mechanical, reological, and processing properties 21, 22.…”

Section: Introductionmentioning

confidence: 99%

Effects of arm number on the properties of transparent elastomers prepared from styrene–butadiene block copolymer

Zhang

2006

J of Applied Polymer Sci

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A series of the SBS transparent elastomers were prepared from star-shaped SBS having different arm number by solution-casting. Their structure and physical properties were characterized by scanning electron microscope, ultraviolet spectrometer, wide-angle X-ray diffractometer, differential scanning calorimetry, dynamic mechanical thermal analysis, tensile testing, and contact angle measurements. The results revealed that the miscibility, optical transparence (T r ), tensile strength ( b ), elongation at break ( b ), and elasticity at low temperature of the star SBS increased with an increase of arm number. The six-arm SBS having relatively high molecular weight exhibited a simultaneous enhancement of T r (90% at 800 nm), b (6.0 Mpa), and b (1260%). This indicated that the SBS materials having six arms had higher transparence and elasticity than others. Moreover, the water contact angle on surface of the starshaped SBS film increased with an increase of arm number that is enhancement of hydrophobicity. Therefore, the relatively high arm number and molecular weight played an important role in the improvement of the miscibility and properties of the SBS sheets as a result of the compacted architecture of the hyperbranched molecules. This work provides a convenient way to obtain materials with both high transparence and elasticity by increasing the arm number.

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Synthesis and characterization of novel biocompatible four-arm star-shaped copolymers by using a new tetramethacrylate core

et al. 2014

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Molecular architectures of four‐arm star‐shaped styrene‐butadiene copolymer

Abstract: ABSTRACT:To understand the molecular architectures of styrene-butadiene four-arm star (SBS) copolymers, a size exclusion chromatography combined with laser light scattering (SEC-LLS) has been used to determine their weightaverage molecular weight (M w

Cited by 3 publications

References 18 publications

Effects of molecular weight and arm number on properties of star‐shape styrene–butadiene–styrene triblock copolymer

Effects of molecular weight and arm number on properties of star‐shape styrene–butadiene–styrene triblock copolymer

Effects of arm number on the properties of transparent elastomers prepared from styrene–butadiene block copolymer

Synthesis and characterization of novel biocompatible four-arm star-shaped copolymers by using a new tetramethacrylate core

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