Preparation of Formaldehyde-free Melamine Resin using Furfural as Condensation Agent and its Retanning Performances Investigation

Abstract

Amino resins are one of the most important retanning agentsused in the leather industry. However, the generally presence offormaldehyde greatly restricts the widespread application ofamino resins. In this study, furfural, an organic compoundderived from biomass material, was used to substitute forformaldehyde in the synthesis of melamine resin based on analkaline-acid procedure. The as-synthesized formaldehyde-freemelamine resin (MRf) showed excellent performances in leatherprocessing. FTIR and 13C-NMR were used to characterize thechemical structure of MRf. The particle size as well as zetapotential were also determined. The retanning performances ofRf indicated that the overall performances of MRf arecomparable to conventional formaldehyde contained melamineresin (MR) and commercial melamine resin (CMR). Inparticular, the thickness of the leather retanned by MRf wasenhanced around 10.33%, which is significantly higher than thatof controls MR (6.16%) and CMR (5.94%). Color measurementsshowed that MRf imparted leather with higher dark intensity.This present work demonstrated that furfural could be apotential candidate to replace formaldehyde in the production offormaldehyde-free melamine resin.