Synthesis and Characterization of Liquid Crystalline Polysiloxanes Containing Terminal Fluoromethyl Groups

摘要

A series of liquid crystalline (LC) polysiloxanes (PI-PV) were prepared by use of poly(methylhydrogeno)siloxane and two kinds of terminal olefinic monomers. The chemical structures and liquid-crystalline properties of the synthesized materials were characterized by various experimental techniques. From PI to PV, the glass transition temperature and the isotropic temperature decreased slightly with increase of terminal fluoromethyl units in the polymer systems. All the monomers and polymers showed nematic phase with wide mesophase temperature ranges. The polymers PI, PII and PIII displayed single nematic mesophase, but PIV and PV bearing more terminal fluoromethyl units showed another smectic mesophase besides nematic mesophase.