Rheology and Morphology of Dynamically Asymmetric LCST Blends: Polystyrene/Poly(vinyl methyl ether)
Rheology and Morphology of Dynamically Asymmetric LCST Blends: Polystyrene/Poly(vinyl methyl ether)
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DOI：
10.1021/ma101421s
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发表时间：
2010-09
期刊：
影响因子：
5.5
通讯作者：
J. K. Yeganeh;F. Goharpey;R. Foudazi
中科院分区：
文献类型：
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作者：
J. K. Yeganeh;F. Goharpey;R. Foudazi
我们研究了动态不对称 PS/PVME 共混物的不同相分离形态的时间演化与相应的线性和瞬态流变行为之间的相关性，其中纯组分的玻璃化转变之间存在很大差异（约 125 °C）。相图是从动态温度扫描实验获得的。采用相差光学显微镜研究了在 105 °C 恒温下获得的相图各个区域的 PS/PVME 共混物的形态演变。在此温度下，根据样品组成，除了常见的相分离机制（成核和生长（NG）和旋节线分解（SD））之外，还观察到粘弹性相分离（VPS），这表明PS/PVME共混物的相分离行为中热力学和粘弹性之间的相互作用。测量不同相分离机制（NG、SD 和 VPS）的线性粘弹性行为，以投资...
We investigated the correlation between the time evolution of the different phase-separating morphologies and corresponding linear and transient rheological behaviors for the dynamically asymmetric PS/PVME blend in which there is a large difference between glass transitions of the pure components (about 125 °C). The phase diagram was obtained from dynamic temperature sweep experiments. Phase contrast optical microscopy was employed to investigate morphological evolution of PS/PVME blends at various regions of obtained phase diagram at a constant temperature of 105 °C. At this temperature depending on sample composition, the viscoelastic phase separation (VPS) was observed besides the usual phase separation mechanisms (nucleation and growth (NG) and spinodal decomposition (SD)), indicating the interplay between thermodynamics and viscoelasticity in phase-separation behavior of PS/PVME blends. The linear viscoelastic behavior for different phase separating mechanisms (NG, SD, and VPS) was measured to invest...