Superglue was rejected twice before anyone realized its value
In 1942, chemist Harry Coover was searching for clear, shatterproof plastics to build precision gun sights for Allied soldiers during World War II. He synthesized cyanoacrylate, but abandoned the formula because it stubbornly stuck to every laboratory tool it touched. Nine years later, while testing heat-resistant polymers for jet canopies at Eastman Kodak, Coover encountered the compound again. This time, he recognized that its instant, room-temperature bonding was an entirely new kind of adhesive.
An Unwanted Polymer in the Wartime Lab
In 1942, the demands of the Second World War drove material scientists into urgent searches for new synthetic materials. Harry Coover, a chemist working with a research team at Eastman Kodak, was tasked with discovering optically clear, shatter-resistant plastics that could be molded into precision gun sights for Allied soldiers. Acrylic polymers were promising candidates because they offered transparency without the fragility of glass. During experiments evaluating various monomer combinations, Coover and his colleagues synthesized a class of organic compounds known as cyanoacrylates.
Instead of producing clean, moldable lenses, the newly synthesized compound immediately adhered to every piece of laboratory apparatus it touched. It bonded glass pipettes, metal spatulas, and casting molds with relentless tenacity. For a team seeking to pour and cast smooth optical components that could easily separate from molds, a substance that permanently fused to mold surfaces was considered a complete failure. Coover logged the compound's behavior, shelved the formula, and turned his focus toward materials better suited for precision casting.
A Broken Refractometer and a Shift in Perspective
Nearly a decade later, in 1951, Coover was working at Tennessee Eastman Company, a division of Eastman Kodak, supervising research into heat-resistant polymers for jet aircraft canopies. High-speed jet aviation placed extreme aerodynamic and thermal stresses on cockpit enclosures, requiring polymers capable of withstanding severe temperature fluctuations without warping or losing structural integrity. As part of this research program, chemist Fred Joyner began synthesizing and testing a series of acrylate monomers, including ethyl cyanoacrylate.
To measure the optical properties of the liquid compound, Joyner placed a drop between the optical prisms of an Abbe refractometer, an expensive precision laboratory instrument. Within seconds, the compound set solid. When Joyner attempted to separate the prisms to clean the device, they were permanently fused together, ruining the instrument. When Joyner reported the mishap, Coover recognized that the material's rapid, unassisted bonding was not an obstacle, but the discovery of a completely unprecedented type of adhesive that required no external heat, solvent evaporation, or mechanical pressure to cure.
The Chemistry of Ambient Polymerization
Traditional adhesives of the mid-twentieth century typically relied on the evaporation of volatile organic solvents or the mixing of two distinct components to initiate a chemical cross-linking reaction. Cyanoacrylates operate through an entirely different chemical pathway known as anionic polymerization. The monomer molecule contains an acrylate backbone flanked by two strongly electron-withdrawing functional groups: a nitrile (cyano) group and an ester group. This arrangement leaves the carbon-carbon double bond highly electron-deficient and exceptionally reactive toward nucleophiles.
Because of this extreme reactivity, cyanoacrylate does not require a specialized chemical catalyst to begin hardening. The initiation trigger is simply ambient moisture. Microscopic films of water, which coat almost every solid surface exposed to Earth's atmosphere, contain trace hydroxide ions and water molecules capable of donating electrons. When liquid cyanoacrylate makes contact with these surface molecules, the nucleophiles attack the electron-deficient double bond, forming a carbanion. This newly formed anion immediately attacks an adjacent monomer, propagating a rapid chain reaction that locks the liquid into an entangled matrix of solid polycyanoacrylate within seconds.
From Industrial Compound to Commercial Phenomenon
Eastman Kodak filed patents protecting the material and brought it to market in 1958 under the trade name Eastman 910. The product was initially directed at manufacturing and industrial assembly lines, where quick-setting adhesives could replace mechanical fasteners or eliminate long clamping cycles. To demonstrate the adhesive's remarkable tensile strength, Coover appeared on national television programs, including the game show 'I've Got a Secret,' where he used a single drop of the compound to suspend an automobile or support heavy platform weights in front of live audiences.
The adhesive possessed extraordinary tensile strength—often exceeding several thousand pounds per square inch when pulling directly against a flat bond. However, early commercial iterations exhibited definite mechanical limitations. While cyanoacrylates resist pulling forces extremely well, their brittle polymeric structure makes them vulnerable to shear stress, impact shock, and peel forces. Over time, chemical formulations were adapted with plasticizers and rubber-toughening additives to expand their utility beyond rigid laboratory joints.
Battlefield Triage and the Medical Evolution
During the Vietnam War, cyanoacrylate transitioned from industrial assembly into emergency medicine. Field medics carried specially packaged cyanoacrylate sprays to treat catastrophic combat wounds. When soldiers sustained severe hemorrhaging, particularly in soft-tissue abdominal organs where traditional clamping or suturing was difficult in the field, medics sprayed the adhesive directly onto the bleeding tissue. The compound solidified upon contact with blood, sealing lacerations instantly and stabilizing patients long enough for them to reach surgical facilities.
Despite saving countless lives, original commercial formulas utilizing methyl or ethyl cyanoacrylate presented clinical complications. As the polymer matrix degraded inside living tissue, it released byproducts including formaldehyde and cyanoacetate, causing localized inflammation, histotoxicity, and tissue necrosis. Consequently, medical researchers developed longer-chain derivatives, such as n-butyl cyanoacrylate and 2-octyl cyanoacrylate. These larger molecular formulations degrade far more slowly, drastically reducing chemical toxicity and allowing cyanoacrylate-based tissue adhesives to become standard, non-invasive alternatives to surgical sutures and staples.
Forensic Fuming and Latent Detection
Beyond structural joining and wound closure, cyanoacrylate plays a foundational role in modern forensic science through a technique known as cyanoacrylate ester fuming. Discovered in the late 1970s by forensic investigators in Japan, the process exploits the monomer's unique reaction kinetics to visualize latent fingerprints on non-porous surfaces like glass, plastics, and metals.
When liquid cyanoacrylate is gently heated inside an enclosed chamber, it vaporizes into an airborne gas. As these monomer vapors circulate, they encounter invisible fingerprint deposits composed of water, fatty acids, amino acids, and proteins left behind by human skin. The trace moisture and basic components in the residue catalyze localized polymerization. The gaseous monomer selectively solidifies directly onto the friction ridge impressions, forming a durable, visible white polymer outline that can be photographed, powdered, or treated with fluorescent dyes for permanent evidentiary preservation.
Thermal Hazards and Material Sensitivities
Because anionic polymerization is a rapid exothermic reaction, the curing process releases heat energy. Under normal household conditions—joining two non-porous surfaces with a thin film—the heat dissipates almost instantaneously into the surrounding substrates. However, when cyanoacrylate comes into contact with natural fibrous materials like cotton or wool, the interaction can become unexpectedly dangerous.
Cotton is composed of cellulose, a polymer rich in hydroxyl groups that act as an exceptionally potent catalyst for cyanoacrylate polymerization. The open, high-surface-area fibrous structure of cotton draws the liquid monomer throughout the fabric by capillary action, triggering simultaneous, uncontrolled polymerization. This rapid release of chemical energy generates enough thermal heat to cause severe skin burns, scorch fabric, and in some instances ignite the cotton fibers. For this reason, laboratory handling guidelines strictly prohibit wearing cotton gloves or cotton clothing when working with bulk volumes of the adhesive.
Key takeaways
•Cyanoacrylate was twice dismissed as a manufacturing nuisance—first as a failed plastic for wartime gun sights in 1942, and again in 1951 when it accidentally ruined an optical refractometer.
•Unlike glues that require heat, drying, or chemical mixing, cyanoacrylate polymerizes instantly at room temperature via an anionic chain reaction triggered by ambient moisture.
•Original short-chain cyanoacrylates used as emergency wound sprays caused tissue inflammation, prompting the creation of longer-chain variants for modern medical closures.
•Contact between cyanoacrylate and cotton fibers causes rapid, uncontrolled exothermic polymerization that can produce severe thermal burns or ignite the fabric.