Influence of Defect Density on the Rheology of Ordered Block Copolymers
Influence of Defect Density on the Rheology of Ordered Block Copolymers
复制标题
缺陷密度对有序嵌段共聚物流变学的影响
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
K. Osaki
中科院分区：
文献类型：
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作者：
N. Balsara;H. J. Dai;H. Watanabe;T. Sato;K. Osaki
静态有序的嵌段共聚物材料包含随机取向的晶粒以及伴随的缺陷和晶界。目前的理论表明，嵌段共聚物的异常流变特性与平均晶粒尺寸（即缺陷密度）有关。我们提供了聚苯乙烯-聚异戊二烯二嵌段共聚物在邻苯二甲酸二辛酯（70 wt% 聚合物）中的浓溶液的流变数据。样品在有序状态下具有圆柱形形态。通过调整热历史，平均晶粒尺寸发生了一个数量级以上的变化（0.4 至 7.4 μm）。然而，这种材料在 10-2−102 rad/s 频率范围内的粘弹性模量并未受到这种变化的显着影响。
Quiescently ordered block copolymer materials contain randomly oriented grains with concomitant defects and grain boundaries. Current theories suggest that the anomalous rheological properties of block copolymers are related to the average grain size, i.e. defect density. We present rheological data from a concentrated solution of a polystyrene−polyisoprene diblock copolymer in dioctyl phthalate (70 wt % polymer). The sample has a cylindrical morphology in the ordered state. The average grain size was changed by over an order of magnitude (0.4 to 7.4 μm) by adjusting thermal history. The viscoelastic moduli of this material in the frequency range 10-2−102 rad/s were, however, not significantly affected by this change.