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Deformation of Hierarchical Lamellar Structure Formed by a Liquid Crystalline Block Copolymer
Author(s) -
Kuribayashi Junpei,
Ishige Ryohei,
Hayashi Mikihiro,
Tokita Masatoshi
Publication year - 2020
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.202000042
Subject(s) - lamellar structure , copolymer , materials science , deformation (meteorology) , liquid crystal , composite material , elongation , crystallography , methacrylate , polymer , chemistry , ultimate tensile strength , optoelectronics
The deformation of a structure of alternating liquid crystal (LC)/viscous layers upon being stretched along the normal layer is investigated using highly ordered, near‐single‐crystal lamellar fibers of an LC block copolymer. The block copolymer consists of poly(ethyl methacrylate) (PEMA) segments attached to a main‐chain LC polyester at both ends. The LC block segregates from the PEMA block and forms a smectic LC, laying the layers parallel to the interface with PEMA block lamellae to form a hierarchical layered structure. Deformations on stretching the fiber sample are observed by X‐ray scattering measurements. The fiber deformation causes lamellae to dilate and undulate at elongation ratio (λ) < 1.6, wherein PEMA block lamellae are preferentially dilated to tilt lamellar boundaries. In the dilated LC block lamellae, the smectic layers undulate without changing the layer spacing. With further fiber elongation, the lamellae are folded into a chevron rather than dilated, recovering the lamellar spacing.