Synthesis and Properties of a Series of Mesogen-Jacketed Liquid Crystalline Polymers with Polysiloxane Backbones

A series of mesogen-jacketed liquid crystalline polymers (MJLCPs) with polysiloxane backbones have been synthesized by hydrosilylation of polymethylhydrosiloxane with styrenic derivatives. Their properties were studied in detail by a combination of ¹H NMR, Fourier transform infrared spectroscopy, differential scanning calorimetry, polarized light microscopy, wide-angle X-ray diffraction, scanning electron microscopy, and contact angle measurements. Wide-angle X-ray diffraction results indicated that these MJLCPs based on highly flexible polysiloxane main chain could also self-assemble into supramolecular columnar nematic or smectic liquid crystalline phases compared with structurally similar MJLCPs having a polyethylene backbone, but their liquid crystalline ranges were narrowed significantly. Low contact-angle values of the MJLCPs could be attributed to the fact that the polysiloxane backbones were embedded in mesogenic side chains, which also confirmed the mesogen-jacketed model for MJLCPs.