Self-healing materials can autonomously repair micro-cracks by mimicking the regenerative ability of biological tissues, thus extending their service life. With the flexibility of molecular chains and chemical activity, silicone rubber has become a research hotspot in the field of self-healing materials.

1. Self-healing Driven by Dynamic Chemical Bonds

Introducing dynamic covalent bonds (such as disulfide bonds and hydrazone bonds) or supramolecular interactions (such as hydrogen bonds and π-π stacking) into silicone rubber to construct a reversible cross-linked network. When the material is damaged, external stimuli (such as heating and light) trigger the breaking and recombination of the bonds, achieving crack healing. For example, silicone rubber containing disulfide bonds can achieve a tensile strength recovery rate of up to 85% after being heated at 80°C for 30 minutes, making it suitable for in-situ repair of aerospace seals.

2. Microcapsule-Encapsulated Repair Agents

Encapsulating repair agents (such as siloxane prepolymers) in microcapsules and dispersing them in the silicone rubber matrix. When cracks propagate, the microcapsules break and release the repair agents, which are cross-linked and cured under the action of a catalyst. Experiments show that silicone rubber with 5 wt% microcapsules can autonomously repair scratches 0.5 mm deep, and the light transmittance can be restored to 95% after repair, making it suitable for self-healing coatings of optical devices.

3. Self-healing with Biomimetic Structures

Inspired by mussel adhesion proteins, grafting dopamine derivatives onto the surface of silicone rubber to form an interfacial layer with reversible adhesion. When the material is separated, the interfacial layer is re-bonded through secondary cross-linking. This biomimetic self-healing silicone rubber has an adhesive strength of up to 1.2 MPa in a humid environment and can be used for the sealing repair of underwater equipment.


General Purpose Fumed Extrusion Silicone Rubber