Synthesis and Properties of Novel T-type Nonlinear Optical Polyurethane Containing Tricyanovinylthienyl Group with Enhanced Thermal Stability of Dipole Alignment

A novel T-type polyurethane 7 containing 1-(2,5-dioxyphenyl)-2-(5-(1,2,2-tricyanovinyl)-2-thienyl)ethenes as NLO chromophores, which constitute part of the polymer backbone, was prepared. Polyurethane 7 is soluble in common organic solvents such as DMF and DMSO. It shows a thermal stability up to 270 degrees C from TGA thermogram with T-g value obtained from DSC thermogram near 155 degrees C. The second harmonic generation (SHG) coefficient (d(33)) of poled polymer film at 1560 nm fundamental wavelength is 3.56 x 10(-9)esu. Polymer 7 exhibits a thermal stability even at 5 degrees C higher than T-g, and no significant SHG decay is observed below 160 degrees C, which is acceptable for nonlinear optical device applications.