Synthesis and linear/nonlinear optical properties of new polyamides with DANS chromophore and silphenylene groups

Abstract Three organic polymeric materials poly[2-((2-ethylene-4-(2-(4-nitrophenyl)vinyl)phenylamino)-ethylene)imino]-[(bis-(4-carbonylphenylene)dimethylsilane)imino], poly[2-((2-ethylene-4-(2-(4-nitrophenyl)vinyl)phenylamino)ethylene)imino]-[(bis-(4-carbonylphenylene)dibutylsilane)imino] and poly[2-((2-ethylene-4-(2-(4-nitrophenyl)vinyl)phenylamino)ethylene)imino]-[(bis-(4-carbonylphenylene)diphenylsilane)imino], which possess both a second-order nonlinear optical (NLO) chromophore and silicon moiety having different lateral group, were prepared by the polycondensation reaction in N -methylpyrrolidinone solution, and their linear and NLO properties, thermal stabilities, and poling efficiency were investigated in details. The magnitudes of NLO coefficient measured under a constant applied voltage of 3.4 kV strongly depend on poling conditions such as a poling temperature, a poling time, a heating rate and a gap distance between electrodes. The resulting films poled under an applied voltage of 3.4 kV at T g −10 °C for 7 min exhibited d 33 =18.0–25.5 pm V −1 in Maker-fringe measurement. The value showed a good thermal stability up to 120 °C.