Preparation and Optical Limiting Properties of Polyurethane Containing Long Conjugated Chromophores.

Two functional polyurethanes (P1 and P2) bearing a large π electron conjugated chromophoric pendant were synthesized and characterized by FT-IR, 1H-NMR and UV-Vis absorption spectra. Their optical limiting properties were evaluated. The results show that P1 and P2 show novel optical limiting properties, which are assigned to a long π electron conjugated chromophoric pendant. It was found that their optical limiting properties were affected simultaneously by solution concentration and P2 displays a better optical limiting property than P1 at the same solution transmittance, although that P1 has larger χ(3) (4.28×10-11 esu) than P2 (0.87×10-11 esu), and their optical limiting mechanism is investigated. [ABSTRACT FROM AUTHOR]