Effect of the concentration of dye on the physical property of dye‐based polyurethane ionomer

Abstract

Abstract We have successfully prepared Congo Red‐based polyurethane ionomers at our lab, and these ionomer structures have been proven by infrared (IR) spectra. For a dye‐based polyurethane ionomer molecule solution, the surface tension was found to decrease, but the number‐average particle size was found to increase with increasing concentration of Congo Red employed to prepare this ionomer molecule. Interestingly, the number‐average particle size of dye‐based polyurethane ionomer molecules decreases with increasing concentration of Congo Red in the presence of other dyes (i.e., Remajol Brilliant Blue R and Amaranth), as a result of Congo Red intramolecular interaction. It is important to point out that the addition of a fixed concentration of Amaranth to prepare Congo Red‐based polyurethane ionomer molecules will significantly enhance the tensile strength but will decrease the elongation of this ionomer molecule. © 1995 John Wiley & Sons, Inc.