Polymer Bulletin, Vol.38, No.2, 157-164, 1997
Chirality Induction in Liquid-Crystalline Side-Chain Polyethers Prepared by Copolymerization of Oxiranes with Mesogenic and Non Mesogenic Groups
Copolymers prepared by anionic initiation from racemic or optically active styrene oxide and a racemic oxirane bearing cyanobiphenyl mesogenic group in the side chain are liquid crystalline when the content of the mesogenic monomer exceeds 60 mole %. Copolymers prepared from a mesogenic oxirane with a short spacer and racemic styrene oxide exhibit a nematic phase, while those prepared with optically active styrene oxide exhibit a cholesteric phase, thus indicating a transfer of chirality from the main chain towards the mesophase. Such a transfer of chirality is no more observed in the case of a copolymer prepared from a mesogenic oxirane with a long spacer.