Room-Temperature Self-Healing Glassy Thermosetting Polymers via Defective Network Design

Abstract

Glassy thermosetting polymers, which possess excellent mechanical properties, structural stability, and solvent resistance, cannot be healed and recycled due to the irreversible crosslinking network. Covalent adaptive networks could address these drawbacks, as their chemical networks are able to shuffle dynamic covalent bonds through exchange reactions, which nevertheless need high temperature or solvent assistance. Here we report a room-temperature self-healing glassy thermoset enabled by designing a disulfide-bond and H-bond hybridized network carrying abundant dangling chains, which are commonly known as network “defects.” However, the “defects” do not plasticize the polymer, as they are bound to network chains through H-bonds. Therefore, the polymer possesses high modulus and strength at room temperature. Importantly, the “defects” can drive the metathesis reaction of disulfide bonds and the rearrangement of H-bonds in the glassy state, enabling the thermosetting network to self-heal at and even below room temperature.