Synthesis and Structure−Property Relationships of Soluble Rigid−Flexible Copolyethers Containing Blue and Yellow Light Emitting Units

Abstract

A series of new rigid−flexible copolyethers containing blue- and yellow-emitting conjugated segments have been synthesized. The thermal, mechanical, and optical properties of the polymers are controlled by the type of the comonomers, their ratio at the preparation stage, and the length of the flexible spacer, as well as the structure of the blue monomer in the main chain. The polyethers were characterized by viscosimetry, thermal and mechanical analysis, NMR, and UV−vis and luminescence spectroscopy. The polymers obtained are soluble in common solvents, form free-standing films either from solution casting or after melt pressing, and show good mechanical properties. Regardless of the excitation wavelength, the polyethers show bright-yellow photoluminescence in solution, suggesting energy transfer from the blue to the yellow unit. In the solid state, the luminescence behavior is controlled by the monomer structure, the molar percentage of the comonomers, the length of the flexible spacer, and the excitatio...