Fusion of Different Crosslinked Polymers Based on Dynamic Disulfide Exchange

Angew Chem Int Ed Engl. 2020 Mar 9;59(11):4294-4298. doi: 10.1002/anie.201913430. Epub 2020 Jan 24.

Abstract

Crosslinked polymers (CLPs) exhibit exceptional mechanical properties as well as good chemical and solvent resistance. However, their reprocessing, recycling, and modification remain difficult. One promising approach to overcome this limitation is to introduce dynamic covalent bonds that enable chain-exchange reactions and network-structure rearrangements in identical polymer networks (A-A fusion), resulting in self-healing and reprocessing properties. Reported here is the fusion of two distinct polymer networks (A-B fusion) by the dynamic behavior of bis(2,2,6,6-tetramethylpiperidin-1-yl)disulfide (BiTEMPS) at the interface between different CLPs. The appearance, swelling behavior, and mechanical properties of the fused samples indicate exchange reactions of the BiTEMPS units and the formation of topological bonds at the interface, commensurate with the generation of a CLP that exhibits tunable properties.

Keywords: dynamic covalent chemistry; mechanical properties; polymers; radicals; sulfur.