Engineering a pioneering melamine resin based on saccharide-derived aldehyde: Structure characterization and application for eco-leather production

Exploring new aldehydes with non-volatility and non-toxicity to replace formaldehyde (FA) for the fabrication of melamine resins (MRs) with eco-friendliness is a topical challenge worldwide. Herein, we report on a novel and facile way to synthesize an eco-friendly MR using a green crop-oriented saccharide-derived aldehyde (SDA) instead of FA. FTIR, NMR and XPS spectra demonstrated that a biomass-derived aldehyde bonded melamine resin (BMR) was synthesized. GPC test showed that the weight average molecular weight of BMR could be up to 4849 g/mol when the mole ratio between SDA and melamine (MA) was 1:1, which decreased as the SDA dosage increased. The application of BMR as a filling agent for leather processing indicated that BMR could improve the hydrothermal stability of filled leather and exhibited reasonable thickening capability. Meanwhile, the BMRtreated crust leather had higher mechanical strengths than melamine FA resin (MFR)-treated crust leather, and it contained almost no FA while the FA content of the MFR-treated crust leather was up to 86.4 mg/kg, indicating the favorable eco-friendliness of BMRs. This work presents a significant step forward for synthesizing environmentally-friendly BMR used in eco-leather production and other MR-involved industries.