Tuning the Thermal Properties of Azopolymers Synthesized by Post-Functionalization of Poly(propargyl Methacrylate) with Azobenzene Azides: Influence on the Generation of Linear and Circular Birefringences

A series of side-chain polymers with a bifunctional repeating unit are prepared by post-polymerization functionalization of poly(propargyl methacrylate) (PPMA) with several azides derived from bis(hydroxymethyl)propionic acid (bis-MPA). The azide incorporates one photoresponsive 4-cyanoazobenzene unit and one photoinert promesogenic moiety at each repeating unit. Both the effect of the photoinert (4-cyanobipheynyl vs 4-cyanotolane) and of the linking group (ester vs carbamate) on the liquid crystalline properties and the generation of optical anisotropy, linear or circular birefringences are explored.