Preparation, Thermo-Optic Property and Transmission Loss of Chiral Azobenzene Polyurethane

A novel chiral azobenzene polyurethane (CAPU) was prepared from chromophore, chiral reagent L(-)-tartaric acid and toluene diisocyanate (TDI). The chemical structure and the thermal property were characterized by UV-Vis spectrum, FT-IR, (1)H NMR, circular dichroism (CD) spectrum, differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). DSC and TGA experiments showed that the glass transition temperature (T(g)) and the decomposition temperature (T(d)) at 5% mass loss were 110 degrees C and 199 degrees C, respectively. The refractive index (n) and thermo-optic coefficient (dn/dT) of the CAPU were measured at 650 nm wavelength and different temperature by attenuated total reflection (ATR) technique. By using CCD digital imaging devices, transmission loss of CAPU was measured and the value is 0.565dB/cm. The results will provide the foundation for many potential applications such as digital thermo-optic switch materials and other fields in the future. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 2567-2572, 2011