Side‐chain liquid crystalline polymers with silphenylene‐siloxane main chains. I. Synthesis of silphenylene‐siloxane polymers containing hydrosilane units

Siophenylene‐siloxane polymers with repeating units containing hydrosilane, SiH, groups were synthesized for use as backbone polymers in side‐chain liquid crystalline polymers. The polymerization of 1,4‐bis (hydroxydimethylsilyl) benzene with a bis (Pyrrolidinyl) silane monomer formed a crosslinked polymer during the course of the reaction, while the use of a bis (ureido) silane monomer gave a polymer which crosslinked on storage after preparation. However, a soluble polymer could be prepared successfully by using a dichlorosilane as the comonomer. Polymers containing two and three SiH groups in each unit were prepared by the last method. All Soluble polymers were characterized by gel permeation chromatography (GPC), infrared spectroscopy (IR) multinuclear NMR spectroscopy, and differential scanning calorimetry (DSC).