A cholesteric mesophase induced in hydrogen-bonded polymer blends with low-molecular-mass chiral additives

Formation of a cholesteric mesophase in hydrogen-bonded complexes based on comb-shaped LC copolymers containing alkyloxy-4-hydroxybenzoic acid (proton donor) fragments and 4-pyridinecarboxylic acid chiral derivatives (proton acceptor) was studied. It was found that blends containing 1-25 mol % of an optically active additive form a chiral nematic phase. The temperature dependences of the selective light reflection wavelength were investigated, and the helical induction power was found. to vary from 12.1 to 20.5 mu m(-1) depending on the structure of the nematic polymer matrix and the length of the rigid. aromatic fragment of chiral additive. With respect to the combination of optical properties, the chiral nematic phase in hydrogen-bonded complexes does not rank below the classical cholesteric copolymers, in which a chiral group is covalently attached to the polymer chain.