Polymeric Dopant Effects of Bent-Core Covalent-Bonded and Hydrogen-Bonded Structures on Banana-Shaped Liquid Crystalline Complexes

Abstract

Two series of banana-shaped liquid crystalline (LC) H-bonded complexes HP(m)/CB(n) (i.e., bent-core H-bonded side-chain homopolymer HP mixed with bent-core covalent-bonded small molecule CB) and CP(m)/HB(n) (i.e., bent-core covalent-bonded side-chain homopolymer CP mixed with bent-core H-bonded small molecular complex HB) with various m/n molar ratios were developed. The bent-core covalent- and H-bonded structural moieties were homopolymerized in the banana-shaped LC H-bonded complexes HP(m)/CB(n) and CP(m)/HB(n), respectively. The influences of m/n molar ratios (polymeric moieties vs. small molecular moieties) on the mesomorphic and electro-optical properties of both banana-shaped LC H-bonded complexes HP(m)/CB(n) and CP(m)/HB(n) were investigated. The polar smectic phases could be achieved and stabilized by smaller contents of polymeric dopants in banana-shaped LC H-bonded complexes, such as HP1/CB10, HP1/CB15, CP1/HB10, and CP1/HB15, which possessed tunable spontaneous polarization (Ps) values according to the molar ratios of m/n, that is, lower Ps values obtained in H-bonded complexes HP(m)/CB(n), and CP(m)/HB(n) with higher ratios of H-bonded moieties (larger m/n molar ratios), respectively. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 764-774, 2010