Why is super glue so strong?

Super glue is made of cyanoacrylate, an acrylic resin that creates a strong bond almost instantly. The molecules of this acrylic resin react on contact with the hydroxyl ions found in water. Because some trace of water can be found on the surface of almost anything, super glue can bond immediately and tightly to almost any object. The cyanoacrylate molecules start to link and form chains, triggered by the water. They spin around in strands that form a super-strong plastic mesh, and they only stop when the glue becomes thick and hardens, and the molecular chains can't move.

The chemical process that super glue undergoes is called anionic polymerization. This dries up the water to create the bond, and the heat this process generates can even burn your skin. If you happen to glue something other than the intended object, like your fingers for example, be careful how you unstick yourself.

Cyanoacrylate's bonding ability is so quick and so strong (a square-inch bond can hold weight of over a ton) that inadvertent finger-sticking often happens. The basic rule of super-glue first aid is not to force anything apart, or you will tear your skin. First remove excess glue, but scrape it off and don't use any kind of fabric, as that may cause a chemical reaction that could burn your skin. Soak your hands in warm soapy water, and then carefully pull your fingers apart using a dull tool.

Take care never to open the super glue cap with your mouth! Loosening super-glued lips is no easy matter. Cyanoacrylate's bonding ability is so strong, it can be used instead of stitches to close up wounds. If super glue is combined with a different alcohol, it becomes less toxic and can be used more safely on the skin.