Cyanoakrilát

Cyanoakrilát is a family of fast-curing adhesives, commonly known as cyanoacrylates. They are esters of cyanoacrylic acid and polymerize rapidly in the presence of trace moisture, forming strong bonds with a wide range of materials, including metals, glass, ceramics, leather, and many plastics.

The curing mechanism is an anionic polymerization initiated by moisture on the surface being bonded. Common variants include methyl, ethyl, propyl, butyl, and octyl cyanoacrylates. Short-chain forms cure very quickly and can be brittle, while longer-chain versions (such as butyl and octyl) offer greater flexibility and are often preferred for medical or dermatological uses. The polymerization is exothermic, and large bonds can generate noticeable heat.

Applications of cyanoakrilát span household repairs, hobbyist and industrial assembly, and specialized medical uses. General-purpose cyanoacrylates are widely used for quick fixes on non-porous surfaces. Medical-grade cyanoacrylates are formulated for tissue adhesion and wound closure and are used in addition to or as an alternative to sutures in certain procedures. Dental and electronic applications also employ cyanoacrylates for bonding small parts and assemblies.

Properties and limitations include strong adhesion to many surfaces but poor bonding to some plastics, especially polyolefins, unless primers or surface treatments are used. They can bond skin within seconds, so handling requires care. Fumes can irritate the eyes, nose, and throat, and the vapors are flammable in the right conditions. Storage typically involves keeping the product in a cool, dry place with inhibitors to prevent premature curing; shelf life is limited once the container is opened.

Cleanup of uncured adhesive is possible with acetone or similar solvents, while cured cyanoacrylate is difficult to remove. Safety data sheets provide detailed handling guidelines.