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Recent advances in the synthesis of block copolymers have enabled the creation of smart and functional designer polymers possessing specific intermolecular interactions. The long-range nature of these interactions strongly affects the molecular packings and microstructures of such polymers, which are intimately related to their properties. In addition to various applications, their unique physicochemical properties, distinguished from conventional block copolymers, are attracting significant attention from polymer and materials scientists. In this review, we describe the current understanding of the structure-property relationship of block copolymers having long-range interactions and suggest possible directions of technological development. We particularly focus on how specific interactions, such as Coulombic, π-π stacking, hydrogen-bonding, and metal/ion-dipole interactions, affect the molecular arrangements of block copolymers on the nanometer and molecular scales. Such information could lead to block copolymers with more advanced functions for future nanotechnologies.

A series of triblock copolymers with liquid crystalline (LC) poly{6-[4-(4-methoxyphenylazo)phenoxy]hexyl methacrylate} (PMMAZO) as the end blocks and rubbery poly(n-butyl acrylate) (PnBA) as the midblock were synthesized. The effect of the interplay between the LC ordering and microphase separation on the hierarchical assembly of the triblock copolymers was studied. It is found that microphase separation at a larger scale can affect the LC ordering at a smaller scale, such as the stacking of the LC moieties, LC temperature and the domain size of the LC phase. On the other hand, alteration of the LC ordering, such as isotropization and smetic-to-nematic transition, may also lead to an order–order transition (OOT) or change in the long period of the microphase-separated structure. UV light can trigger the isomerization of the azobenzene LC moieties, which can be further amplified and exerts an effect on the microphase separation behavior, including the regularity of the microphase-separated structure and the OOT. The triblock copolymers also exhibit light-variable tensile properties. The results reveal that the phase behavior and mechanical properties of this type of triblock copolymer can be readily regulated by light, thus it may be used as smart and functional thermoplastic elastomer.