Controlling kink band morphology in block copolymers : Threshold criteria and stability
Controlling kink band morphology in block copolymers : Threshold criteria and stability
复制标题
控制嵌段共聚物中的扭结带形态：阈值标准和稳定性
DOI：
--
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
K. Winey
中科院分区：
文献类型：
--
作者：
Daniel L. Polis and;K. Winey
缺陷的产生、结构和动力学控制着材料的结构和物理性能。在这项工作中，扭结带缺陷系统地引入到层状聚（苯乙烯-b-乙烯丙烯）二嵌段共聚物通过施加不同的速率和总应变的稳态剪切。然而，扭折带只有在剪切应变超过一个临界值时才产生。仅仅存在的扭结带意味着存在一个优先滑移面平行于lamellae，我们估计存在于聚苯乙烯微区。此外，我们的研究结果的扭折带的几何形状的剪切速率和应变的依赖性表明，这些缺陷是由旋转的lamicum。基于旋转机制，扭结带的特征尺寸和它们的空间分布，似乎是预先存在的缺陷引发扭结带。从稳态剪切诱导的扭结带获得的见解扩展到振荡剪切排列的这种高分子量的二聚体。
The initiation, structure, and dynamics of defects control both the structure and physical properties of materials. In this work, kink band defects are systematically introduced into a lamellar poly(styrene-b-ethylene propylene) diblock copolymer by applying various rates and total strains of steady shear. However, kink bands are only produced when the shear strain exceeds a critical value. The mere existence of kink bands implies the presence of a preferential slip plane parallel to the lamellae, which we estimate exists within the polystyrene microdomains. Furthermore, our results regarding the dependence of kink band geometry on shear rate and strain suggest that these defects are formed by the rotation of lamellae. Based on a rotation mechanism, the characteristic size of the kink bands and their spatial distribution, it appears that preexisting defects initiate kink bands. Insights gained from steady-shear-induced kink bands are extended to oscillatory shear alignment of this high molecular weight di...