Liquid crystalline polyethers have been synthesized from 1-(4-hydroxy-4‘-biphenylyl)-2-(4-hydroxyphenyl)propane and α,ω-dibromoalkanes with even-numbers of methylene units [TPP(n = even)s]. Multiple phase transitions are found during cooling and heating via differential scanning calorimetry (DSC), and they show little undercooling dependence. Ordered structure identifications are based on experimental observations of wide angle X-ray powder and fiber diffraction experiments at different temperatures. Polarized light and transmission electron microscopy observations on mesophase morphology combined with DSC results on thermodynamic transition properties also provide additional evidence for these phase assignments. Moreover, the contributions of the mesogenic groups and the methylene units to each ordering process are obtained based on the changes of transition enthalpy and entropy. In TPP(n ≤ 8)s the highest temperature transition is from the isotropic melt to a nematic phase. This nematic phase is only stable in a narrow temperature range. For instance, it is 12 °C for TPP(n = 4) and 6 °C for TPP(n = 8). When the number of methylene units n ≥ 10, the isotropic melt directly enters a smectic F phase. The second transition in TPP(n ≤ 8)s is from the nematic to the smectic F phase. As a result, the smectic F phase exists for all TPP(n = even)s. Decreasing the temperature further leads to another transition in TPP(n = even)s to form a smectic crystal G phase which is followed by a transition to a smectic crystal H phase. This smectic crystal H phase remains for TPP(n ≤ 8)s down to their glass transition temperatures, while in TPP(n ≥ 10)s further ordering processes occur and crystal phases are observed. A phase diagram of TPP(n = even)s is constructed.

The series of new chiral nematic ionomers containing 0.7-9.0 mol % ions of alkali metals Na and transition metals Co(II) were synthesized by the exchange reaction between chiral nematic N* functionalized liquid crystalline (LC) copolymers bearing the phenylbenzoate mesogenic fragment, optically active moiety (derivatives of cholesterol), and carboxylic groups with acetate of cobalt and sodium. For ionomers containing 0.7-9 mol % sodium ions the melting point is independent of temperature. At the same time, the incorporation of cobalt ions in the polymer matrix leads to decreasing of clearing temperature and destruction of the mesophase at the concentration of transition metal higher than 6 mol %. All ionomers produce the chiral nematic phase, which is characterized by selective light reflection the spectral range 500-2000 nm. The introduction of even small amounts of metal ions to functionalized LC copolymer prevents untwisting of pitch of the helix with decreasing the temperature. This tendency is related to a limited translational mobility of side groups in the LC copolymer, which produce helical structure, due to the physical network as formed by charged groups.

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