Synthesis And Electro-Optic Properties Of Novel Y-Type Polyimide Containing Nitrothiazolylazodioxyphenyl Group

New Y-type polyimide (5) containing nitrothiazolylazodioxyphenyl groups as nonlinear optical (NLO) chromophores, which are components of the polymer backbone, was prepared and characterized. Polyimide 5 is soluble in common organic solvents such as N,N-dimethylformamide and dimethylsulfoxide. Polyimide 5 shows a thermal stability up to 300??C in thermogravimetric analysis with glass-transition temperature (T-g) obtained from differential scanning calorimetry near 130??C. The second harmonic generation (SHG) coefficient (d(33)) of poled polymer film at the 1064?nm fundamental wavelength is around 2.32?pm/V. The dipole alignment of polymer 5 exhibits a thermal stability even at 5??C higher than T-g, and there is no SHG decay below 135??C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.