Synthesis and Self-Assembly of Rod鈥揜od Block Copolymers with Different Rod Diameters

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• 作者：Feng Zhou ; Tieying Ye ; Lingying Shi ; Chan Xie ; Shankui Chang ; Xinghe Fan ; Zhihao Shen
• 刊名：Macromolecules
• 出版年：2013
• 出版时间：October 22, 2013
• 年：2013
• 卷：46
• 期：20
• 页码：8253-8263
• 全文大小：921K
• 年卷期：v.46,no.20(October 22, 2013)
• ISSN：1520-5835

文摘

We synthesized a series of rod鈥搑od block copolymers, poly(octyl-4鈥?(octyloxy)-2-vinylbiphenyl-4-carboxylate)-b-poly(纬-benzyl-_l-glutamate) (PVBP-b-PBLG) with different rod diameters, and we focused on the effect of size disparity on their self-assembling behaviors in bulk. By using differential scanning calorimetry, wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering, and transmission electron microscopy techniques, we found that the columnar nematic (桅_N) liquid crystalline phase of PVBP and the hexagonal columnar (桅_H) phase of PBLG were disrupted to different extents depending on the volume fractions of PVBP (f_PVBP鈥檚). When f_PVBP is about 60%, the 桅_H phase of PBLG is retained with the appearance of the two second-order diffractions in WAXD patterns. When f_PVBP is increased to above 73%, the ordered structure of PBLG is destroyed, and when f_PVBP is 91% even the first-order diffraction peak disappears. At the same time, the 桅_N phase of PVBP changes from poorly ordered to well ordered with increasing f_PVBP. Accordingly, with f_PVBP increasing from 60% to 91%, the microphase-separated structure goes through a poorly ordered structure to an interdigitated lamellar morphology and to a bilayer lamellar structure.