History of Adhesives
The word “adhesive” is simple yet represents the foundation of a multi-billion dollar global industry, encompassing over 750 companies competing for market share. Recent research shows that around 50 of these companies account for 50% of sales in the adhesive industry.
Evidence of adhesive use dates back to 4000 BC. Studies of prehistoric burial sites reveal that sticky resins from tree sap were used to repair pottery. Babylonian temple statues indicate the use of a tar-like adhesive to attach ivory eyes to eye sockets.
Further historical evidence from 1500 to 1000 BC shows wall paintings depicting adhesive use in wood bonding, notably in the construction of Tutankhamun’s coffin. Museums worldwide house numerous ancient artifacts showcasing early adhesive or laminating techniques with animal glue, especially from Egyptian tombs. By around 200 BC, simple methods for producing and using animal glue were referenced in literature.
The history of adhesives continued from 1 to 500 AD, when Romans and Greeks utilized adhesives to bond thin wood layers, refining animal and fish glues and employing various natural materials like egg whites, blood, bones, skins, milk, cheese, and vegetables. Additionally, wax was used for waterproofing wooden boards in boats.
While many historical adhesive applications have faded, by 1700 AD, adhesives became essential and were quickly produced. The first commercial adhesive factory in the Netherlands made animal glue from hide, leading to the first adhesive patent in Britain for fish glue in 1750. This spurred numerous patents for adhesives using natural rubber, animal bones, fish, starch, and milk proteins, with many factories in the U.S. producing adhesive by 1900.
The Industrial Revolution rapidly advanced technological developments, leading to new materials in adhesive production, beginning with the first plastic polymer from cellulose nitrate, originally used for billiard balls. The plastic era began in 1910 with the production of phenolic Bakelite, a thermoset plastic. Following this, the use of phenolic resins in adhesive production expanded quickly, alongside many new synthetic plastics and rubbers created between 1920 and 1940, many of which were developed during World War II.
World War II spurred the rapid growth of the synthetic adhesive industry, prompting manufacturers to consider flexibility, toughness, curing time, and temperature/chemical resistance in their production processes.
Today, adhesives are used in countless applications, replacing sewing, stapling, and fastening in many manufacturing processes. Adhesives have become an integral part of our daily lives, available in various forms derived from natural and synthetic sources. How can you stay updated with the ever-evolving technology? Join us to keep abreast of industry news and trends.
Diverse Applications of Adhesives
Since the 19th century, synthetic adhesives produced in laboratories have largely overshadowed plant and animal adhesives. The adhesive industry is rapidly growing, with few modern human-made devices not utilizing adhesives. From simple boxes to airplanes, various adhesives and sealants are employed in a wide range of products.
Building Industry
Adhesives are crucial in construction, from high-pressure PVC pipe adhesives to silicone sealants (aquarium glue), tile adhesives, wallpaper adhesives, stone adhesives, and even 123 glue for wooden structures like MDF cabinets, wood glue, as well as polyurethane foams and mastics widely used for insulation and sealing gaps.
Components of Adhesives
Polymeric Materials (Polymers)
All adhesives contain polymers, which provide adhesion strength through polymerization reactions during curing. Polymers can be viewed as chains of chemically linked units, connected by covalent bonds. They become fluid at high temperatures and dissolve in appropriate solvents. This flow property is crucial in thermosetting adhesives and the solubility of solvent-based adhesives. Network polymers do not flow upon heating; they may swell in solvents but do not dissolve, making construction adhesives network-based to eliminate creep (deformation under constant load).
Other Additives in Adhesives and Sealants
Many adhesives, in addition to polymers, contain additives such as:
- Stabilizers against degradation from oxygen and UV rays.
- Plasticizers to enhance flexibility and lower the glass transition temperature (Tg).
- Mineral fillers to reduce shrinkage during curing and improve flow properties before curing, enhancing final mechanical properties.
- Lubricants mainly added to improve the injection process or application of adhesives under pressure.
