Preparation and characterization of the water-soluble polymer dye from N,O-carboxymethyl chitosan

In this paper, a new kind of water soluble polymer dye was prepared through reaction of reactive Brilliant Red K-2BP with N,O-carboxymethyl chitosan in the alkaline condition. It was demonstrated that the dye was grafted onto the chain of N,O-carboxymethyl chitosan through the results of FT-IR and ¹H-NMR. It is detected that the maximum absorbing wavelength and the molar absorptivity ε of K-2BP in the 0.1 mol/L Na₂CO₃-0.1 mol/L NaHCO₃ buffer solution is 526 nm and 18918.0 L/mol·cm respectively. Then it can be calculated that the grafting degree of reactive Brilliant Red K-2BP on the chain of the N,O-carboxymethyl chitosan is 1 : 10.4.