Hierarchically-Ordered Nanoscopic Structures from Complex Polymeric Systems: Effect of Chain Connectivity

Abstract

This review reports on hierarchical structures formed by complex polymeric materials such as block copolymers and/or polymer blends. The topics and their principal achievements are as follows. The polymer components used are polyiosprene(I), polystyrene(S), poly(2-vinylpyridine)(P) and poly(4-hydroxystyrene)(H), and almost all the polymer samples were prepared by anionic polymerizations and therefore have narrow molecular and composition distribution. 1) Complex structures from multiblock terpolymer: Undecablock terpolymers of the PISISISISIP type and hexablock terpolymers of the PISISI type with both have much different block chain lengths show hierarchical structures with double periodicity. 2) Periodic and aperiodic tiling structures from star-shaped terpolymers: Bulk structures of IXSYPZ star-shaped terpolymers were observed and simply periodic Archimedean tiling structures and quasicrystalline tiling structures with dodecagonal symmetry have been found. 3) New self-assembly manner of block copolymer/homopolymer blend: A polystyrene-b-poly(2-vinylpyridine)(SP) diblock copolymer and H homopolymer can be mixed together to form periodic two-phase structures because of hydrogene bonding interaction between P and H components. 4) Supramacromolecular self-assembly by ionic bonding interaction: Polystyrene with 13 styrene sulfonic acid units on one chain end and polyisoprene with amino group on one chain end tend to form periodic two-phase structures due to acid/base ionic bonding depending on compositions.