Sustainable bisphenols for thio-catechol adhesives: Fundamentals of scalable oxidation, polymerization, and light-switchable mechanisms of adhesion & debonding

该项目侧重于通过巯基醌聚添加剂合成受自然启发的TCC粘合剂，重点是通过有机工艺开发和材料合成的协同作用利用生物资源。计划调查的目标是双重的。在有机方法开发方面（BUW, AK Kirsch），重点将放在研究和建立天然存在的酚类与相应醌的直接氧化反应，同时确保可扩展性和遵守绿色原则。由于该转化的标准试剂2-碘氧基苯甲酸（IBX）是爆炸性的，因此挑战在于开发间歇和连续的二酚-双醌氧化催化工艺，并促进催化剂的可回收性。在材料合成和聚合物应用方面（HUB, AK Börner），可持续双醌与多硫醇聚合的研究是一个关键方面，其最终目标是使生物基tcc -聚合物适用于粘合剂应用。利用咖啡酸的[2+2]光环产物的衍生物，tcc -聚合物网络将被获取并研究其光切换裂解和光响应重组能力。这些材料允许在脱粘和重粘领域的高要求应用的探索，但也调查有趣的概念，如光刺激愈合粘合缺陷。

The project focuses on the synthesis of nature-inspired TCC adhesives via thiol-quinone polyadditions, with an emphasis on the utilization of bioresources through the synergy of organic process development and material synthesis. The objectives of the planned investigations are twofold. On the side of organic method development (BUW, AK Kirsch), the focus will be on the investigation and establishment of a direct oxidation reaction of naturally occurring phenols to their corresponding quinones, while ensuring scalability and adherence to green principles. Since the standard reagent for this transformation, 2-iodoxybenzoic acid (IBX), is explosive in large quantities, the challenge is to develop batch and continuous catalytic processes for diphenol-bisquinone oxidation and to facilitate catalyst recyclability. On the side of material synthesis and polymer application (HUB, AK Börner), the study of sustainable bisquinones for the polymerization with multithiols is a key aspect, with the ultimate aim of enabling bio-based TCC-polymers suitable for adhesive applications. Using derivatives of the [2+2] photocyclization product of caffeic acid, TCC-polymer networks will be accessible and studied for their light-switchable cleavage and photoresponsive reorganization capability. These materials allow the exploration of highly demanded applications in the field of debonding and rebonding, but also the investigation of interesting concepts such as photostimulated healing of adhesion defects.