Superglue is a common household adhesive known for its ability to create rapid and powerful bonds between various materials. This instant bonding capability stems from a precise chemical reaction first accidentally discovered by scientists searching for clear plastic gun sights during World War II. The quick-setting substance was later commercialized, becoming the fast-acting repair solution widely used today. The secret to its strength and speed lies in its simple liquid composition and its reaction to a ubiquitous natural element.
The Core Ingredient
The basic component of superglue is a class of chemical compounds known as cyanoacrylates, typically ethyl cyanoacrylate. This substance is a liquid monomer, a small molecule that can link up with others to form long chains. Inside the sealed tube, the liquid monomer is combined with an acidic stabilizer to prevent premature bonding. This acidic environment keeps the cyanoacrylate molecules in their liquid, unreactive state. The glue remains stable as long as the acidic conditions are maintained and the container remains airtight.
The Role of Moisture and Polymerization
The bonding process begins the moment the liquid glue is exposed to the environment. Trace amounts of water, present as moisture in the air or on the surfaces being joined, act as a trigger. This moisture de-acidifies the liquid, neutralizing the stabilizers that kept the monomer unreactive. The presence of these water molecules initiates a rapid chemical process called anionic polymerization.
During this reaction, the cyanoacrylate monomer molecules quickly link together to form long, chain-like polymer structures. This process is so fast that the glue sets in seconds, forming a rigid, glassy plastic mesh that physically interlocks with the microscopic irregularities of the bonded surfaces. The polymerization is an exothermic reaction, meaning it releases heat as the chemical bonds form. This heat release is noticeable if a large amount of glue is used or if it contacts fibrous materials like cotton. The resulting polymer is the hardened adhesive that provides the bond.
Deactivating the Bond
Once the cyanoacrylate monomer has polymerized, the cured superglue is essentially a type of plastic highly resistant to water. Breaking this bond requires a substance that can chemically attack and dissolve the polymer chains. The most effective substance for this purpose is the organic solvent acetone, often found in nail polish remover. Acetone works by weakening the molecular bonds that hold the polymer chains together, dissolving the hardened plastic.
To remove cured superglue, acetone can be applied to the affected area. The solvent penetrates the polymer structure, breaking it down into smaller, more soluble components. This allows the hardened glue to soften and be wiped or scraped away. Because acetone is a strong solvent, care must be taken when using it on certain materials like painted surfaces or some types of plastic, as it can cause damage.