Editing Cyanoacrylate (section)

==Properties==

In its liquid form, cyanoacrylate consists of monomers of cyanoacrylate molecules. Methyl-2-cyanoacrylate (CH2=C(CN)COOCH3 or C5H5NO2) has a molecular weight equal to 111.1, a flashpoint of 79 °C, and 1.1 times the density of water. Ethyl-2-cyanoacrylate (C6H7NO2) has a molecular weight equal to 125 and a flashpoint of >75°C. To facilitate easy handling, adhesives made with cyanoacrylate are usually formulated so that the glue is more viscous and gel-like.

Generally, cyanoacrylate is an acrylic resin which rapidly polymerises in the presence of water (specifically hydroxide ions), forming long, strong chains, joining the bonded surfaces together. Because the presence of moisture causes the glue to set, exposure to moisture in the air can cause a tube or bottle of glue to become unusable over time. To prevent an opened container of glue from setting before use, it must be stored in an airtight jar or bottle with a package of silica gel.

Another important trait is that cyanoacrylate sets quickly, often in less than a minute. A normal bond reaches full strength in two hours and is waterproof. Accelerators such as toluidine trigger setting in two or three seconds, with some loss of strength.

Acetone, which is commonly found in nail polish remover, is a widely available solvent capable of softening cured cyanoacrylate. Nitromethane is also an excellent solvent. Methylene chloride is the most effective solvent, but is toxic. Gamma-butyrolactone is also effective at removing cured cyanoacrylate, and has low toxicity.

Low temperatures cause cured cyanoacrylate to become brittle. Cyanoacrylate's bonds can be weakened (allowing disassembly) by placing a glued object in a household freezer for several hours. Opened containers of cyanoacrylate glue can also be delayed from prematurely setting by storing the containers in the household refrigerator.

[[Category:Science]]