Cyanoacrylate Glue (Super Glue™)
Cyanoacrylate Glue (Super Glue™) Information
Cyanoacrylate is the generic name for a family of fast-acting adhesives with industrial, medical and household uses. They include methyl 2-cyanoacrylate, ethyl-2-cyanoacrylate (commonly sold under trade names like "Super Glue" and "Krazy Glue"), and n-butyl cyanoacrylate (used in veterinary and skin glues). The related compound 2-octyl cyanoacrylate is a medical grade glue; it was developed to be non-toxic and less irritating to skin tissue. Cyanoacrylate adhesives are sometimes known as instant glues. The abbreviation "CA" is commonly used for industrial grades.
Cyanoacrylate Glue (Super Glue) Uses
Cyanoacrylate glue has a low shearing strength, which has also led to its use as a temporary adhesive in cases where the piece can easily be sheared off at a later time. Common examples include mounting a workpiece to a sacrificial glue block on a lathe, and tightening pins and bolts.
Cyanoacrylates are used to assemble prototype electronics (see wire wrap), flying model aircraft, and as retention dressings for nuts and bolts. Their effectiveness in bonding metal and general versatility have also made them popular among modeling and miniatures hobbyists. They are used to re-harden the boxes and shanks of ballerinas' pointe shoes as well.
Cyanoacrylate glue's ability to resist water has made it popular with marine aquarium hobbyists for fragging corals. The cut branches of hard corals such as Acropora can be glued to a piece of live rock (harvested reef coral) or Milliput (epoxy putty) to allow the new frag to grow out. It is actually safe to use directly in the tank, unlike silicone, which must be cured to be safe. However, as a class of adhesives, traditional cyanoacrylates are classified as having "weak" resistance to both moisture and heat although the inclusion of phthalic anhydride reportedly counteracts both of these characteristics.
In most cases, standard cyanoacrylate adhesive does not functionally bond well with smooth glass, although it can be used as a quick, temporary bond prior to application of a proper glass epoxy or cyanoacrylate specifically formulated for use on glass. A mechanical adhesive bond may be formed around glass fibre mat or tissue to reinforce joints or to fabricate small parts.
When added to baking soda (sodium bicarbonate), cyanoacrylate glue forms a hard, lightweight filler/adhesive (baking soda is first used to fill a gap then the adhesive is dropped onto the baking soda). This works well with porous materials that the glue does not work well with alone. This method is sometimes used by aircraft modelers to assemble or repair polystyrene foam parts. It is also used to repair small nicks in the leading edge of composite propeller blades on light aircraft. Note that the reaction between cyanoacrylate and baking soda is very exothermic (heat-producing) and also produces noxious vapors. See Reaction with cotton below.
Cyanoacrylate is used as a forensic tool to capture latent fingerprints on non-porous surfaces like glass, plastic, etc. Cyanoacrylate is warmed to produce fumes that react with the invisible fingerprint residues and atmospheric moisture to form a white polymer (polycyanoacrylate) on the fingerprint ridges. The ridges can then be recorded. The developed fingerprints are, on most surfaces (except on white plastic or similar), visible to the naked eye. Invisible or poorly visible prints can be further enhanced by applying a luminescent or non-luminescent stain.
Thin CA glue also has application in woodworking. It can be used as a fast drying, glossy finish. The use of oil (such as boiled linseed oil) may be used to control the rate at which the CA cures. CA glue is also used in combination with sawdust (from a saw or sanding) to fill voids and cracks. These repair methods are used on piano soundboards, wood instruments, and wood furniture.
Some rock climbers use cyanoacrylate to repair damage to the skin on their fingertips. Similarly, stringed-instrument players can form protective finger caps (in addition to calluses) with cyanoacrylates.
CA glue was in veterinary use for mending bone, hide, and tortoise shell by at least the early 1970s. Harry Coover said in 1966 that a CA spray was used in the Vietnam War to retard bleeding in wounded soldiers until they could be brought to a hospital. Butyl cyanoacrylate has been used medically since the 1970s outside the US, but, due to its potential to irritate the skin, the U.S. Food and Drug Administration did not approve its use as a medical adhesive until 1998 with Dermabond. Research has demonstrated the use of cyanoacrylate in wound closure as being safer and more functional than traditional suturing (stitches). The adhesive has demonstrated superior performance in the time required to close a wound, incidence of infection (suture canals through the skin's epidermal, dermal, and subcutaneous fat layers introduce extra routes of contamination), and final cosmetic appearance.
Cyanoacrylate is used in Archery to glue fletching to arrow shafts. The special 'fletch-tite' glues are really Cyanoacrylate repackaged in special fletching glue kits. Often these tubes have a long thin metal nozzle to aid in better accuracy in the application of the glue to the base of the feather or plastic fletching to ensure a good bond to the arrow shaft.
Cyanoacrylate is used in the cosmetology / beauty industry as an adhesive for some artificial nail enhancements such as nail tips and nail wraps.