Dialdehyde sodium alginate (DSA) is an eco-crosslinker attracting extensive interest while undergoing limited large-scale applications. Herein, we employed DSA to react with dicyandiamide (DA) for engineering a biomass-derived retanning agent (BDR) towards addressing the long-term toxicity of residual formaldehyde (FA) in leather caused by amino resins. Results confirmed that BDR reserved the structural features of DSA by grafting DA onto DSA molecules. Owing to the suitable molecular weight (main components, 1424–1462 g/mol) and abundant oxygen-containing groups of BDR endowed by DSA, BDR-treated chrome-free leather showed higher hydrothermal stability (82.4 °C), thickening ratio (13.93 %), mechanical strengths (17.2 N/mm² for tensile strength and 120 N/mm for tear strength), and fullness compared with industrial dicyandiamide-FA-resin (DFR)-treated leather. The FA-free feature of DSA led to BDR-treated leather containing no FA, while FA in DFR-treated leather reached 591.5 mg/kg. This work provided new insights into broadening the large-scale application scopes of DSA.

二醛海藻酸钠 (DSA) 是一种生态交联剂，在进行有限的大规模应用时引起了广泛的兴趣。在此，我们使用 DSA 与双氰胺 (DA) 反应，以设计一种生物质衍生的复鞣剂 (BDR)，以解决由氨基树脂引起的皮革中残留甲醛 (FA) 的长期毒性。结果证实，BDR通过将DA接枝到DSA分子上而保留了DSA的结构特征。由于 DSA 赋予 BDR 合适的分子量（主要成分，1424-1462 g/mol）和丰富的含氧基团，BDR 处理的无铬皮革表现出更高的水热稳定性（82.4 ℃）、增稠率（13.93 %)，机械强度 (17.2 N/mm ²拉伸强度和撕裂强度 120 N/mm)，以及与工业双氰胺-FA 树脂 (DFR) 处理的皮革相比的丰满度。DSA 的无 FA 特性导致 BDR 处理的皮革不含 FA，而 DFR 处理的皮革中的 FA 达到 591.5 mg/kg。这项工作为扩大 DSA 的大规模应用范围提供了新的见解。