Cover Image, Volume 50, Issue 14


original image

The synthesis of segmented theromotropic copolyesters containing azobenzene through melt polycondensation are depicted, as presented by Chinmay G. Nardele and S. K. Asha on page 2770. The structural design incorporating azobenzene as part of a twin molecule with a central oligooxyethylene spacer facilitates polymerization by meltcondensation by reducing the melting temperature of the twin molecule and also by improving solubility and miscibility in the molten reaction medium. The incompatibility of the polar oligooxyethylene spacer units with the rigid rod-like azobenzene results in segregation leading to mesophase formation. The liquid crystalline (LC) characteristics of the polymer could be tuned depending on the chemical structure of the azo chromophore as well as the length of the central oligooxyethylene segment.