Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7202, USA.
ACS Appl Mater Interfaces. 2011 Dec;3(12):4804-11. doi: 10.1021/am201297f. Epub 2011 Nov 29.
Forced assembly processing provides a unique opportunity to examine the effects of confinement on block copolymers (BCPs) via conventional melt processing techniques. The microlayering process was utilized to produce novel materials with enhanced mechanical properties through selective manipulation of layer thickness. Multilayer films consisting of an elastomeric, symmetric block copolymer confined between rigid polystyrene (PS) layers were produced with layer thicknesses ranging from 100 to 600 nm. Deformation studies of the confined BCP showed an increase in ductility as the layer thickness decreased to 190 nm due to a shift in the mode of deformation from crazing to shear yielding. Postextrusion annealing was performed on the multilayer films to investigate the impact of a highly ordered morphology on the mechanical properties. The annealed multilayer films exhibited increased toughness with decreasing layer thickness and resulted in homogeneous deformation compared to the as-extruded films. Multilayer coextrusion proved to be an advantageous method for producing continuous films with tunable mechanical response.
强制组装处理通过常规的熔融加工技术提供了一个独特的机会来研究约束对嵌段共聚物（BCP）的影响。微层压工艺被用于通过选择性地控制层厚度来生产具有增强机械性能的新型材料。由弹性对称嵌段共聚物在刚性聚苯乙烯（PS）层之间被限制的多层膜的层厚度范围为 100 至 600nm。受限 BCP 的变形研究表明，随着层厚度减小到 190nm，延展性增加，这是由于变形模式从银纹化转变为剪切屈服。对多层膜进行挤出后退火处理，以研究高度有序形态对机械性能的影响。与挤出的薄膜相比，退火后的多层薄膜表现出韧性随层厚度的减小而增加，并且导致均匀变形。多层共挤出被证明是一种生产具有可调机械响应的连续薄膜的有利方法。
