Synthesis and Dyeing Properties of Three Hemicyanine-Based Fluorescent Polymeric Dyes

This research deals with the synthesis of hemicyanine-based fluorescent polymeric dyes and their use in acrylic dyeing. Three new hemicyanine dyes were synthesized by the Knoevenagel reaction, and grafted to carboxymethylchitosan (O-CMC) to form polymeric dyes. The resulting dyes were characterized using ¹ H-NMR and ¹³ C-NMR spectroscopy, indicating that these polymeric dyes were successfully synthesized. The practical utility of these polymeric dyes was demonstrated by their successful application on acrylic fabrics to give highly fluorescent colors. The fluorescence, color characteristics, and photostability of these dyed fabrics were tested using a fluorescence spectrometer, a spectrophotometer, and a lightfastness tester. Results showed that acrylic fabrics dyed with these polymeric dyes were fluorescent and had better photostability than the parent dyes.