Synthesis and nonlinear optical properties of novel polyester containing nitrothiazolylazoresorcinoxy group

Abstract

ABSTRACTNovel Y-type polyester 4 containing 4-(5-nitro-2-thiazolylazo)re-sorcinoxy group as nonlinear optical (NLO) chromophore, which constitutes parts of the polymer backbone, was prepared and characterized. Polyester 4 is soluble in common organic solvents such as N,N-dimethylformamide and acetone. Polyester 4 shows a thermal stability up to 240°C from thermogravimetric analysis with glass-transition temperature obtained from differential scanning calorimetry of near 106°C. The second harmonic generation (SHG) coefficient (d33) of poled polymer film at the 1064 nm fundamental wavelength is 8.43 × 10−9 esu. The poled polymer film exhibits an enhanced thermal stability of dipole alignment and there was no negligible decay of the SHG signal over hundreds of hours at 70°C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.