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Abstract
A series of new side chain cholesteric liquid crystalline polysiloxanes was synthesized by grafting copolymerization of a mesogenic monomer (M1 ) and a chiral monomer (M2 ). The chemical structures of the monomers and polymers obtained were confirmed by FTIR, and 1H and 13C NMR spectroscopy. The mesomorphic properties were investigated by differential scanning calorimetry, polarizing optical microscopy, and X‐ray diffraction. The influence of the content of the chiral unit on phase behaviour of the polymers is discussed. Monomer M1 showed nematic and smectic phases on cooling. The polymers P1 and P2 showed a nematic phase, P3 –P5 showed cholesteric Grandjean texture, and P6 and P7 exhibited smectic short‐rod texture. The polymers containing more than 7.2 mol % and less than 28.6 mol % of the chrial unit showed an induced cholesteric phase. Experimental results demonstrated that the glass transition, melting and clearing temperatures decreased with increasing content of the chiral unit.
Acknowledgements
The authors are grateful to the National Natural Science Fundamental Committee of China, the HI‐Tech Research and development program (863) of China, the National Basic Research Priorities Programme (973) of China, the Science and Technology Research Major Project of the Ministry of Education of China, and the Science and Technology Bureau of Shenyang for financial support of this work.