Stretching PEO-PPO Type of Star Block Copolymer Gels: Rheology and Small-Angle Scattering
Stretching PEO-PPO Type of Star Block Copolymer Gels: Rheology and Small-Angle Scattering
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星形嵌段共聚物凝胶的拉伸 PEO-PPO 型：流变学和小角散射
DOI：
10.1021/acsmacrolett.8b00792
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发表时间：
2018
影响因子：
7.015
通讯作者：
Kell Mortensen and Masahiko Annaka
中科院分区：
文献类型：
--
作者：
Hiroki Ishikawa;Tim Chung;Gaku Fukuhara;Hajime Shigemitsu;Toshiyuki Kida;Thorsten Bach;Tadashi;中 建介;Hiroko Yamada;Kell Mortensen and Masahiko Annaka
基于聚（环氧乙烷）和聚（环氧丙烷）的交联Tetronic星星嵌段共聚物凝胶在机械性能方面表现得非常规则，但表现出异常的缺乏对应变的结构响应。的弹性响应是线性的超过100%的应变，与稳态模量的顺序为0.01 MPa后的初始应力松弛。中子和X射线散射实验表明，一个一致的，但意想不到的单轴应变的反应，没有变化的特征分子尺寸。当应变超过约100%时，即当应力-应变曲线不再是线性时，结构织构出现并且在进一步应变时变得甚至更明显，因此，表明自组装的六边形有序圆柱形胶束与垂直于应变的圆柱轴对齐。提出了大幅度应变下的主要结构响应与交联星星分子的层状结构有关。
Cross-linked Tetronic star block copolymer gels, based on poly(ethylene oxide) and poly(propylene oxide), behave quite regular with respect to mechanical properties, but exhibits unusual absence of structural response to strain. The elastic response is linear up to more than 100% strain, with a steady-state modulus of the order of 0.01 MPa after an initial stress relaxation. Neutron and X-ray scattering experiments show a consistent but unexpected response to uniaxial strain, with no changes in characteristic molecular dimensions. Upon strain beyond about 100%, that is, when the stress–strain curve is no longer linear, structural texture appears and becomes even more pronounced upon further strain, thus, indicating alignment of the self-assembled hexagonally ordered cylindrical micelles with the cylinder-axis perpendicular to the strain. It is proposed that the main structural response to large-amplitude strain is related to a layer-dominated structure of cross-linked star molecules.