Synthesis and Nonlinear Optical Properties of Novel Polyester Containing Tricyanovinylthiophene with Enhanced Thermal Stability of Second Harmonic Generation

A novel Y-type polyester (7) containing 1-(2,4-dioxyethoxy)phenyl-2-{5-(1,2,2-tricyanovinyl)-2-thiophenyl)}ethenyl groups as NLO-chromophores was synthesized and characterized. Polymer 7 was soluble in common organic solvents such as DMF and DMSO. It showed thermal stability up to 300°C in TGA with T g value obtained from DSC near 134°C. The second harmonic generation (SHG) coefficient (d 33 ) of poled polymer film at the 1,560 nm fundamental wavelength was around 6.74 × 10−9 esu. The dipole alignment exhibited high thermal stability and there was no SHG decay below T g due to the partial main-chain character of polymer structure, which was acceptable for NLO device applications.