Supramolecular self-assembly nature of a novel thermotropic liquid crystalline polymer containing no conventional mesogens

Abstract

Two-dimensional correlation infrared spectroscopy (2DIR) and a newly developed perturbation correlation moving window (PCMW) technique was employed to study the precise supramolecular self-assembly nature of poly[di(butyl)vinyl terephthalate] (PDBVT), a novel thermotropic liquid crystalline polymer which can self-assemble into a two-dimensional hexagonal columnar (2D Φ_H) phase without conventional mesogens. PCMW had found the weak phase transition temperature to be about 85 °C, and further divided the “S or anti-S” shaped spectral variations into three evolving stages. 2DIR results indicated that carbonyl groups acted as the starting point of molecular motions upon heating, and had a significant influence on the formation of the 2D Φ_H phase. Based on the additional motion sequence of symmetric and asymmetric C–H stretching vibrations, the whole self-assembly process of PDBVT on the mesoscale, whose backbones experienced “extension–distortion–slight extension” consecutive motions was elucidated.