A new NLO polyurethane with a tricyanovinyl group

Abstract

A new functionalized polyurethane structure with a heteroaromatic thiophene ring having a tricyanovinyl group in the polymer side chain was synthesized. The resulting polymer was soluble in N-methylpyrrolidinone and could be processed into good optical quality films by spin casting at ca. 100 degrees C. The second-order nonlinear coefficient, d(33), was determined to be 51 pm/V from measuring the second harmonic generation (SHG) for a thin polymer film. The outstanding orientational stability of the aligned chromophores was observed up to about 150 degrees C, which originated from the rigid polymer backbone and the stabilizing function of the hydrogen bridges formed between the neighboring polyurethane chains.