Synthesis and Characterization of Liquid Crystalline Polysiloxanes Containing Benzyl Ether Mesogens

摘要

Side chain liquid crystalline polysiloxanes were synthesized by the hydrosilation of poly(methylhydrosiloxane) with p-(1-undecenyl-11-oxy) benzyl ethers of: 4-cyanophenol (IM), 4-methoxyphenol (IIM), 4-cyano-4'-hydroxybiphenyl (IIIM), 4-methoxy-4'-hydroxybiphenyl (IVM) and 2-cyano-6-hydroxynaphthalene (VM). The phase behavior of both monomeric and polymeric liquid crystals was characterized by differential scanning calorimetry and optical polarization microscopy. IM is a monotropic liquid crystal, IIM is crystalline, IIIM and IVM are enantiotropic liquid crystals, while VM presents two virtual liquid crystalline transitions and crystalline polymorphism. All the synthesized polysiloxanes present enantiotropic smectic mesomorphism.