Crab Shell Chemical Will Give Cars A Self-healing Skin

摘要

You might never need fear for your car's paintwork again if a new kind of polyurethane that can repair its own scratches makes it to market. Previous self-healing materials have mostly used some form of liquid epoxy that is encapsulated in microscopic spheres orfibres, or is delivered by an engineered vascular system. When it is damaged, the epoxy is released into the gap and sets when it makes contact with a hardening agent contained in the material itself. The new self-healing coating works in a different way. Scratches to its surface close up in only a few minutes when exposed to sunlight. This occurs because the damaged polymer molecules around the edges of a scratch absorb energy from the ultraviolet radiation in the sunlight and use it to form new cross-links, and so rebuild its molecular network.