Weldable and Closed-loop Recyclable Monolithic Dynamic Covalent Polymer Aerogels

Owing to their low density, high porosity and unique micro-nanostructures, aerogels are attractive for applications in various aspects, but at the same time, suffer from shrinkage and/or cracking during preparation, mechanical brittleness, low production efficiency, and non-degradation. Herein, we introduce the concept of dynamic covalent polymer chemistry to produce a new class of aerogelsreferred to as DCPAs. The resulting light DCPAs display large-scale preparation prospect and feature high porosity (90.7-91.3%), large degrees of compression (80% strain) and bending (diametral deflection of 30 mm) without any cracks, as well as considerable tensile property (elongation at break of 32.7%). In addition, our DCPAs showcase emergent characteristics of weldability, repairability, and closed-loop recyclability that are highly desirable for affording versatile materials platforms but hardly achieved by traditional aerogels. Benefiting from the robust porous structures, we demonstrate the potential of the DCPAs for applications in thermal insulation and emulsion separation.