A second columnar liquid crystalline phase formed by polymers with highly tapered side chains

Abstract

Previous work has shown that polymethacrylates with highly tapered side groups, such as poly{2‐{2‐[2‐(2‐methacryloyloxyethoxy)‐ethoxy]ethoxy}ethyl‐3,4,5‐tris‐(p‐dodecyloxy‐benzyloxy)benzoate} (H12‐ABG‐4EO‐PMA), form columnar hexagonal (Colh, previously designated φh) liquid crystalline structures. The small angle X‐ray data for drawn fibers of H12‐ABG‐4EO‐PMA, and also those of its hydroxy‐terminated monomer precursor and decyloxy‐homologue, contain several weak equatorial Bragg reflections in addition to those characteristic of the Colh phase. The intensities of these extra reflections decline progressively on heating and disappear before the temperature of the Colh‐to‐isotropic transition is reached. It is proposed that the as‐drawn fibers contain a second phase, which is probably a columnar liquid crystalline structure in view of the decreases in the observed d‐spacings with increasing temperature. The additional reflections are indexed by a two dimensional monoclinic lattice, which probably contains columns with elliptical cross‐section. The lower symmetry is consistent with the formation of a tilted columnar phase analogous to those formed by certain low molecular weight discotic materials.

Self‐organized liquid‐crystalline polyethers obtained by grafting tapered mesogenic groups onto poly(epichlorohydrin): Toward biomimetic ion channels

“…8). Similar behavior has been observed by Chvalun and coworkers 45,46 with the same mesogenic side unit and a methacrylate backbone, but in this article they found higher dimensions of the unit cell (ca. a ϭ 60 Å ) that contained seven to eight disks.…”