Hybrid liquid-crystalline block copolymers

The synthesis and some thermal properties of three series of block copolymers comprising both main-chain and side-chain liquid-crystalline (LC) blocks in the same macromolecular structure are described. The Former block is a semiflexible LC polyester (block B), and the latter is an LC polymethacrylate (block A) containing a variously substituted mesogenic unit. The two structurally different blocks were partly phase-separated within the glassy and LC states and underwent distinct phase transitions. Significant deviations of the transition enthalpies relative to those of the corresponding homopolymers suggest the occurrence of a more or less diffuse interphase which may depend on the nature of the mesophase formed.