Visualization and Quantification of Penetration/Mass Transfer of Acrylic Resin Retanning Agent in Leather using Florescent Tracing Technique

Abstract

Acrylic resin is a widely used retanning agent in leatherprocessing, and its retanning effectiveness is closely related to itspenetration depth and filling parts in leather. But acrylic resin inleather cannot be visualized or quantified, and thus itsapplication mainly depends on tanners’ experience. In this study,5-aminofluorescein-labeled poly(acrylic acid) (AF-PAA), as amodel of fluorescent acrylic resins, was synthesized using aphase-transfer reaction and then purified using Sephadex gelfiltration. AF-PAA was applied to retanning process and couldbe well visualized and quantified in retanned leathers usingfluorescence microscopy and Image J software. Looser collagenfibers, increasing amount of acrylic resin or retanning togetherwith some anionic retanning agents could enhance penetration/mass transfer of acrylic resin in leather. The fluorescent tracingtechnique is useful to investigate the mass transfer and reactionmechanism of acrylic resin in leather processing.