Synthesis and Thermal-Optic Properties of Azo Polyurethane Containing Chiral Unit

摘要

A new chromophore containing azo group, 3,3'-dichloro-4,4'-di-(4-amino-azo-phenyl) -diphenylmethane (CAAPM), was synthesized based on 3,3'-dichloro-4,4'-diaminc— diphenylmethane, sodium nitrite and benzenamine via diazo-coupling reaction. Azobenzene polyurethane (PU) containing chiral unit was obtained from CAAPM, chiral reagent L(-)-tartaric acid and isophorone diisocyanate (IPDI). The chemical structures of CAAPM and PU were characterized by FT-IR and UV-Vis spectroscopy. The measurements of refractive index (n) and thermo-optic coefficient (dnldT) of polyurethane were demonstrated at complex light. The values of n and dnldT were used to calculate the dielectric constant (e) and its variation with temperature (dz/dT). The dn/dT is 4.2000—-3.7000 x l0~(40)°C~(-1). The conclusion has a little significance to develop new the digital optical switch (DOS).