Synthesis and Nonlinear Optical Properties of Novel Y-Type Polyurethane Containing Cyanovinylthiazole

Abstract

A novel Y-type polyurethane 4 containing 5-methyl-4-{5-(1,2,2-tricyanovinyl)-2-thiazolylazo}resorcinoxy groups as nonlinear optical (NLO)-chromophores, which constituted parts of the polymer backbones, was prepared and characterized. Polyurethane 4 is soluble in common organic solvents such as acetone and N,N-dimethylformamide. It showed a thermal stability up to 250°C in thermogravimetric analysis thermogram and the glass-transition temperature (T g ) obtained from differential scanning calorimetry thermogram was around 118°C. The second harmonic generation (SHG) coefficient (d 33 ) of poled polymer film at 1560 nm fundamental wavelength was around 8.43 × 10−9 esu. The dipole alignment exhibited a thermal stability even at 12°C higher than T g , and there was no SHG decay below 130°C due to the partial main-chain character of the polymer structure, which is acceptable for nonlinear optical device applications.