Abstract

The polymers of the 2-cyanoacrylic esters, more commonly known as the alkyl 2-cyanoacrylates, are hard glassy resins that exhibit excellent adhesion to a wide variety of materials. The polymers are spontaneously formed as very reactive liquids, and the excellent adhesion properties of the cured resins combine to make these compounds a unique class of single-component, ambient-temperature-curing adhesives of great versatility. The materials that can be bonded run the gamut from metals, plastics, most elastomers, fabrics, and woods to many ceramics. The cyanoacrylic esters are prepared via the Knoevenagel condensation reaction, in which the corresponding alkyl cyanoacetate reacts with formaldehyde in the presence of a basic catalyst to form a low molecular weight polymer. Subsequently, the polymer is cracked and redistilled at a high temperature onto a suitable stabilizer combination to prevent premature repolymerization. Good ventilation when using the adhesives is essential. Both the liquid and cured 2-cyanoacrylic esters support combustion. Some of the market segments served by these versatile materials include automotive, electronic, hardware, cosmetics, and medical devices.