Preparation and Nonlinear Optical Properties of Novel Polyesters with Enhanced Thermal Stability of Second Harmonic Generation

2,5-Di-(2'-hydroxyethoxy)-4'-nitrostilbene (3) was prepared and polycondensed with terephthaloyl chloride, adipoyl chloride, and sebacoyl chloride to yield novel T-type polyesters (4-6) containing the NLO-chromophores dioxynitrostilbenyl groups, which constituted parts of the polymer backbones. Polymers 4-6 are soluble in common organic solvents such as acetone and N,N-dimethylformamide. They showed thermal stability up to 260℃in thermogravimetric analysis with glass-transition temperatures obtained from differential scanning calorimetry in the range 90-95℃. The second harmonic generation (SHG) coefficients (d33) of poled polymer films at the 1064 nm fundamental wavelength were around 1.42 ´ 10-9 esu. The dipole alignment exhibited high thermal stability up to 5 ℃ higher than glass-transition temperature (Tg), and there was no SHG decay below 100 ℃ due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications. 2,5-Di-(2'-hydroxyethoxy)-4'-nitrostilbene (3) was prepared and polycondensed with terephthaloyl chloride, adipoyl chloride, and sebacoyl chloride to yield novel T-type polyesters (4-6) containing the NLO-chromophores dioxynitrostilbenyl groups, which constituted parts of the polymer backbones. Polymers 4-6 are soluble in common organic solvents such as acetone and N,N-dimethylformamide. They showed thermal stability up to 260℃in thermogravimetric analysis with glass-transition temperatures obtained from differential scanning calorimetry in the range 90-95℃. The second harmonic generation (SHG) coefficients (d33) of poled polymer films at the 1064 nm fundamental wavelength were around 1.42 ´ 10-9 esu. The dipole alignment exhibited high thermal stability up to 5 ℃ higher than glass-transition temperature (Tg), and there was no SHG decay below 100 ℃ due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications. KCI Citation Count: 6