The crosslinked poly(azomethine-urethane)s containing o-hydroxyazomethine: Tunable multicolor emission, photophysical and thermal properties

Abstract

This article presents synthesis, photophysical, electrochemical, thermal, and morphological properties of the crosslinked polyurethanes (CLPUs). CLPUs were synthesized in two main steps. In the first step, aldehyde functionalized polyurethane prepolymer was synthesized using 2,4-dihydroxy benzaldehyde and hexamethylene diisocyanates. In the second step, the prepared prepolymer was converted to the crosslinked polyurethane derivatives using different diamines via condensation reaction. Diamines with various chain length and side-group substitutions were used as crosslinker. Photophysical properties of the crosslinked polyurethanes were investigated using UV-vis and photoluminescence (PL) spectra techniques. Fluorescence measurements showed that CLPUs exhibited multicolor emission behavior. Additionally, a linear relationship is determined between the excitation energies and the obtained emission maxima and, this property allows tuning the PL color by changing the source light energy on the desired scale. (C) 2015 Elsevier B.V. All rights reserved.