Preparation of a novel Y-type nonlinear optical polyester with high, second harmonic generation thermal stability

Abstract 2,4-Di-(2′-hydroxyethoxy)benzylidenemalononitrile was prepared and condensed with terephthaloyl chloride to yield a novel Y-type polyester containing dioxybenzylidenemalononitrile, nonlinear optical chromophores as part of the polymer backbone. The resulting polymer was soluble in common organic solvents such as acetone and N , N -dimethylformamide and displayed thermal stability up to 300 °C with a glass-transition temperature of ∼94 °C. The second harmonic generation coefficient ( d 33 ) of poled polymer film at the 1064 nm fundamental wavelength was 6.48 × 10 −9  esu. The dipole alignment exhibited high thermal stability even at 10 °C higher than T g and there was no second harmonic generation decay