Harnessing dynamic covalent chemistry in sustainable biomass-based polymers: synthesis, dynamic functionalities and potential of dithiolane-containing supramolecular polymers

Most plastics in use today are derived from petrochemical resources, resulting in severe environmental problems. As fossil resources are depleting, polymers derived from sustainable feedstock and manufacturing routes have become increasingly in demand. However, producing bio-based polymeric materials with desired properties remains challenging. Recently, 1,2-dithiolane-containing molecules, such as biogenic thioctic acid, have gained substantial attention as promising feedstocks for developing polymers with advanced features. These molecules can be widely found in animals and plants, and feature a unique five-membered disulfide ring that endows the derived polymers with a combination of functions and properties that rarely appear in traditional biogenic polymers or classical supramolecular polymers. These include responsiveness, biocompatibility, biomedical function, self-healing capability, adhesiveness, recyclability, degradability and tuneable mechanical properties spanning from soft to stiff, without requiring elaborate synthetic processes. In this review, we provide a comprehensive review of the recent advancement in 1,2-dithiolane-containing polymers, summarising their preparation strategies, comparing the latest advances in their properties and discussing their corresponding applications. Finally, we discuss the challenges that need to be addressed in order to integrate these materials harmonically into our daily lives. This review is expected to promote the exploration in the functionalities and applications of sustainable dynamic covalent biomass-based polymers.