A Polyurethane-based Retanning Agent with Fluorescent Effect

Abstract

A novel fluorescent waterborne polyurethane retanning agent (FWPRA) was prepared through chemically incorporation of fluorescer, disodium 4, 4’-bi s[4 - a n i l i no - 6 - hydroxyethylamino-6-(2-choloronilino-1,3,5 triazin-2-yl) amino]stilbene-2,2’-disulphonate (RSW), into polyurethane backbone as a chain extender. The chemical structure was characterized by FTIR, 1H NMR and UV?vis spectrophotometer, and fluorescence performances of FWPRA, RSW together with resultant leather were investigated systematically. The results indicate that polymerization has a positive effect on optical performance; FWPRA shows enhanced fluorescence intensity in comparison with fluorescer RSW. In the retanning process, no decay of optical performance can be found when chromium(III) salt and chestnut extract are used together, which reveals that FWPRA presents good fluorescence stability to other chemicals. For wet blue retanned by FWPRA, the shrinkage temperature, thickness as well as mechanical properties are improved. Most importantly, the resultant leather exhibits magic fluorescence effect under UV lamp.