Preparation and Application of Collagen-Based Waterborne Polyurethane Retanning Agent

A collagen-based waterborne polyurethane retanning agent was prepared by prepolymerization, using isophorone disocyanate (IPDI), polytetramethylene ether glycol (PTMG, Mn=2000), 1, 4-butanediol (BDO), dimethylol propionic acid (DMPA) and triethylamine (TEA), the collagen powder was added during the synthesis to modify the waterborne polyurethane. The collagen-based waterborne polyurethane was characterised via Fourier transform infrared spectroscopy (FT-IR) and size analysis, the results showed that the collagen was grafted onto the main chain of polyurethane, the emulsion had a uniform particle size distribution, the average particle size was 70nm. The prepared emulsion was used in retanning, the application result showed that the collagen-based waterborne polyurethane retanning agent had a good effect for leather filling, especially in the belly. The shrinkage temperature, tensile strength and tear resistance were all raised. The retannage can also help to overcome the question of pastel shades.