原位染色型生物基醛鞣剂的呈色机理及性能调控研究

有机无铬鞣剂的研制与应用是当前解决制革工业铬污染的重要方向。但由于现有有机鞣剂鞣制革坯普遍存在释放甲醛、对染料的吸收结合差等问题，其应用范围受到极大限制。申请人前期研究发现，糖类生物基醛鞣剂（BAT）具有鞣制和原位染色双重功能，有望成为解决上述问题的有效途径，但受原料分子结构的影响，BAT仍存在含甲醛的风险以及鞣革呈色单一的问题。鉴于此，本项目拟通过研究糖基生物质本征结构与甲醛产生及BAT鞣性间的构效关系，制备无甲醛且鞣性良好的BAT，并通过建立多尺度模拟反应体系，从分子水平上阐明其对皮胶原纤维的交联-呈色机理。根据BAT的分子结构及呈色特征，进一步对其进行多样化结构修饰，创制鞣革呈色丰富的BAT，并研究不同BAT间的配伍呈色规律，以此建立其鞣染性能的调控机制。本项目的开展可为原位染色型环保有机鞣剂在无铬生态皮革制造中的应用提供理论支撑，对推动皮革产业的生态可持续发展具有重要意义。

The development and application of organic chrome-free tanning agent is the important direction for solving the chrome pollution in leather industry. However, the existing organic tanning agents tanned leathers generally have problems such as formaldehyde release and poor absorption-fixation of dyes, which severely restrict their widespread applications. Our previous work suggested that the bio-based aldehyde tanning agent (BAT) derived from saccharides has the dual functions of tanning and in-situ dyeing, and is expected to be an effective way to solve the above-mentioned problems. However, due to the impact of the molecular structure of raw materials, BAT still has the risk of containing formaldehyde, and the color of BAT tanned leather is single. In view of this, this project intends to investigate the structure-property relationships among the intrinsic structure of saccharide-based biomass, the formation of formaldehyde and the tanning effect of BAT, thus preparing formaldehyde-free BAT with favorable tanning effect. Next, the crosslinking-coloring mechanism of BAT for skin collagen fibers will be clarified from the molecular level by establishing a multi-scale simulation reaction system. Moreover, according to the molecular structure and coloring features of BAT, further diverse modifications will be conducted to fabricate different BATs that can endow tanned leather with rich colors. Then, the coloring compatibility of different BATs will be studied to establish the regulation mechanism of the tanning-dyeing performances. This project can provide theoretical support for the application of environmentally friendly organic tanning agents with in-situ dyeing property in the manufacture of chrome-free ecological leather, and is of great significance to boost the ecological and sustainable development of leather industry.