Abstract：
Leather shavings are generated as solid waste in the leather industry and may cause environmental pollution if not disposed judiciously. These solid wastes, primarily composed of collagen fibers (CFs), can be recycled as biomass composites. However, CFs are incompatible with natural rubber (NR) due to its hydrophilicity. Conventionally, the compatibility has been improved by utilizing silane coupling agents (SCAs) along with a large number of organic solvents, which further contribute to environmental pollution. In this study, we developed a novel complex coupling agent (CCA) to enhance the compatibility between CF and NR. The CCA was synthesized through a coordination reaction between Cr(III) and α-methacrylic acid (MAA). Cr(III) in the coupling agent coordinates with the active groups in CFs, while the unsaturated double bonds in MAA facilitate covalent crosslinking between the CCA and NR, improving compatibility. The coordination bonding between CF and NR exhibits strong interfacial interaction, endowing the composites with desirable mechanical properties. Moreover, the proposed method is an economical and green approach that can be used to synthesize CF-based composites without requiring organic solvents. Herein, a strategy promoted sustainable development in the leather industry has been established.
摘要：
皮革屑在皮革工业中作为固体废物产生，如果不明智地处理，可能会造成环境污染。这些固体废物,主要由胶原纤维（CFs）组成，可以作为生物质复合材料回收利用。然而,由于其亲水性,CFs与天然橡胶(NR)不相容。传统上,通过使用硅烷偶联剂(SCAs)和大量有机溶剂,这进一步加剧了环境污染。在这项研究中,我们开发了一种新型的复合偶联剂（CCA），以增强CF和NR之间的相容性。CCA是通过Cr（III）与α-甲基丙烯酸（MAA）之间的配位反应合成的。偶联剂中的Cr（III）与CFs中的活性基团配位，而MAA中的不饱和双键促进CCA和NR之间的共价交联，提高兼容性。CF和NR之间的配位键表现出强的界面相互作用，赋予复合材料理想的机械性能。此外，所提出的方法是一种经济，绿色的方法，可用于合成CF基复合材料而无需有机溶剂。在这里，制定了促进皮革工业可持续发展的战略。
