Synthesis and properties of polymer containing azo-dye chromophores for nonlinear optical applications

Some thermal stable polyimides and polyimide/silica hybrid materials containing azo-dye have been synthesized. The resulting polyimides had high weight-average molecular weight (Mw) up to 49 300 and 53 900, respectively, and a large glass transition temperature (Tg) of 242 °C, and the decomposition temperature (Td) of 350 °C. The resulting polyimide/silica hybrid materials had higher glass transition temperature and decomposition temperature than the pure polyimides. The silica content in the hybrid materials varied from 0 to 22.5 wt%. The electro-optic coefficients (γ33) at the wavelength of 832 nm for polymer thin films poled were in the range of 9–23 pm/V and the values remained well (retained >83% for more than 100 h). The heat capacities of some materials were in the range of 0.8433–1.2564 J K−1 g−1 for the temperature range from 273 to 363 K. No thermal anomaly was found in this temperature range.