Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya, Japan.
J Phys Condens Matter. 2011 Jul 20;23(28):284111. doi: 10.1088/0953-8984/23/28/284111. Epub 2011 Jun 27.
Star-shaped terpolymers of the ABC type composed of incompatible polymer components give a variety of ordered structures with mesoscopic length scales depending on their composition ratio. Their peculiar features are summarized in this report. Polymer components adopted are polyisoprene (I), polystyrene (S) and poly(2-vinylpyridine) (P), and many monodisperse samples of the I(X)S(Y)P(Z) type were anionically prepared. Firstly our focus is on molecules of the I(1.0)S(1.0)P(x(1)) type, where x(1) is only a variable. The complex but systematic morphology change was displayed within the range 0.2 ≤ x(1) ≤ 10, that is, their structures change from spherical plus lamellae structure for I(1.0)S(1.0)P(0.2) to periodic tilings (0.4 ≤ x(1) ≤ 1.9), then to lamellae-in-lamella (3.0 ≤ x(1) ≤ 4.9) and lamellae-in-cylinder (7.9 ≤ x(1) ≤ 10) structures with increasing x(1). Here if we pay attention to the structural variation of the P domain inclusively, it transforms from sphere to cylinder, lamella and then to matrix, which is the same as that for linear polymers. Among them, several periodic Archimedean tiling patterns can be naturally formed when the relative lengths of the three chains are close to one another. Moreover, it has been found that the tiling zone is spread out widely. For example, the series I(1.0)S(1.8)P(x(2)) (with 0.8 ≤ x(2) ≤ 2.9) and the other series I(1.0)S(y)P(2.0) (with 1.1 ≤ y ≤ 2.7) show mostly Archimedean tilings. Additionally, block copolymer/homopolymer blends with a composition of I(1.0)S(2.7)P(2.5) reveal a quasicrystalline tiling with dodecagonal symmetry. Furthermore, a zinc-blende-type four-branched network structure was created just a little outside of the tiling region for a block copolymer/homopolymer blend of I(1.0)S(2.3)P(0.8). When some more asymmetry in chain length is introduced, hyperbolic tiling on a gyroid membrane has successfully been constructed for the sample I(1.0)S(1.8)P(3.2) and it transforms into a hierarchical cylinders-in-lamella structure with further increase in P content to I(1.0)S(1.8)P(6.4). Thus, kaleidoscopic morphologies have been generated from ABC star-shaped terpolymers and their structural change has turned out to be very sensitive to relative compositions.
星型三嵌段共聚物由不相容的聚合物组成，根据其组成比例，可以形成具有介观长度尺度的各种有序结构。本报告总结了它们的特殊性质。采用的聚合物组分是聚异戊二烯（I）、聚苯乙烯（S）和聚（2-乙烯基吡啶）（P），并通过阴离子聚合制备了许多单分散的 I(X)S(Y)P(Z) 型样品。首先，我们关注的是 I(1.0)S(1.0)P(x(1)) 类型的分子，其中 x(1) 只是一个变量。在 0.2 ≤ x(1) ≤ 10 的范围内，显示出复杂但系统的形态变化，即它们的结构从 I(1.0)S(1.0)P(0.2) 的球形加片层结构变为周期性平铺（0.4 ≤ x(1) ≤ 1.9），然后变为片层内片层（3.0 ≤ x(1) ≤ 4.9）和片层内圆柱（7.9 ≤ x(1) ≤ 10）结构，x(1) 增加。在这里，如果我们关注 P 域的结构变化，它从球体变为圆柱、片层，然后变为基体，与线性聚合物相同。其中，当三条链的相对长度接近时，几种周期性阿基米德平铺图案可以自然形成。此外，已经发现平铺区分布很广。例如，I(1.0)S(1.8)P(x(2)) 系列（0.8 ≤ x(2) ≤ 2.9）和其他 I(1.0)S(y)P(2.0) 系列（1.1 ≤ y ≤ 2.7）主要显示阿基米德平铺。此外，I(1.0)S(2.7)P(2.5) 的嵌段共聚物/均聚物共混物显示具有十二面体对称性的准晶平铺。此外，对于 I(1.0)S(2.3)P(0.8) 的嵌段共聚物/均聚物共混物，在平铺区之外稍微有点锌矿型四叉形网络结构。当引入更多的链长不对称性时，成功构建了 I(1.0)S(1.8)P(3.2) 的超双曲平铺在准晶胞膜上，并且随着 P 含量的进一步增加，它转化为具有分层圆柱内片层结构的 I(1.0)S(1.8)P(6.4)。因此，从 ABC 星型三嵌段共聚物产生了万花筒形态，其结构变化对相对组成非常敏感。
