Thermotropic Liquid Crystalline Polymers with Various Alkoxy Side Groups: Thermal Properties and Molecular Dynamics

Two series of thermotropic liquid-crystalline polymers (TLCPs) were synthesized by reacting various dialkoxy terephthalate units with hydroquinone (HQ) and 2,6-naphthalene diol (Naph). The dialkoxy terephthalate moieties used in this study include 2,5-diethoxyterephthalate, 2,5-dibutoxyterephthalate, and 2,5-dihexyloxy-terephthalate. All the TLCPs synthesized in this study formed nematic phases. The molecular motions according to the length of the dialkoxy side groups in the TLCPs were evaluated by 13C cross-polarization/magic angle spinning nuclear magnetic resonance spectroscopy. The thermal properties and molecular dynamics of the TLCPs are found to be affected by the length of the dialkoxy side group and the aromatic diol unit in the main chain. Further, the thermal behaviors, liquid crystalline mesophases, and degree of crystallinity of the two series of TLCPs, i.e., HQ- and Naph-TLCPs, are compared.

Synthesis of novel thermotropic liquid crystalline polymers by a reactive extrusion process

The syntheses of new thermotropic liquid crystalline polymers (TLCPs) were carried out via the polyaddition reactions of diepoxy-containing mesogens and a monoamine (1-naphthylamine).

A facile synthetic route to novel thermotropic liquid crystalline polymers and characterization of their mesophases

We have succeeded in preparing novel liquid crystalline polymers of low melting temperature by a melt reaction between diepoxy molecules and a primary monoamine (aniline).