History of Adhesives.

History of Adhesives. The earliest use of adhesives was discovered in 2001 in Italy. At this site, two stone flakes partially covered with birch-bark-tar and a third uncovered stone from the Middle Pleistocene era (circa 200,000 years ago) were found. This is thought to be the oldest discovered human use of tar hafted stones.

The birch-bark-tar adhesive is a simple, one component adhesive. Although sticky enough, plant based adhesives are brittle and vulnerable to environmental conditions. The first use of compound adhesives was discovered in Sibudu, South Africa. Here, 70,000 year old stone segments that were once inserted in hafts, covered with and adhesive composed of a combination of plant gum and red ochre (natural iron oxide), were found. Adding ochre to plant gum produces a stronger produce and protects the gum from disintegrating under wet conditions.[6] The ability to produce stronger adhesives allowed middle stone age humans to attach stone segments to sticks in greater variations and led to the development of new tools.

More recent examples of adhesive use by prehistoric humans has been found at the burial sites of ancient tribes. Archaeologists studying the sites found that approximately 6,000 years ago, the tribesmen had buried their dead with food found in broken clay pots repaired with tree resins. Another investigation by archaeologists uncovered the use of bituminous cements in the fastening of ivory eyeballs to statues in Babylonian temples dating all the way back to approximately 4,000 B.C.E.

In 2000, a paper revealed the discovery of a 5,200 year old man nicknamed the "Tyrolean Iceman" or Oetzi preserved in a glacier near the Austria-Italy border. With him were found several of his belongings including two arrows with flint stone arrowheads and a copper hatchet, each with evidence of organic glue use for the connecting of the stone or metal parts to the wooden shafts. The glue was analyzed as pitch, which requires the heating of tar during its production. The retrieval of this tar requires a transformation of birch bark by means of heat, in a process known as pyrolysis.

A Reconstructed Copy of Oetzi's Axe The first references to adhesives in literature first appeared in approximately 2,000 B.C.E. Further historical records of adhesive use are found from the period starting 1,500 B.C.E. and ending 1,000 B.C.E. Artifacts from this period include paintings depicting wood glueing operations and a casket made of wood and glue in King Tut's Tomb.Other ancient Egyptian artifacts employ the use of animal glue in bonding or lamination. Such lamination of wood for bows and furniture is thought to have extended its life and was conducted with the use of casein (milk protein) based glues. The ancient Egyptians also developed starch based pastes for the bonding of papyrus to clothing and a plaster of Paris like material made of calcined gypsum.

From 1-500 C.E. the Greeks and Romans made great contributions to the development of adhesives. Veneering and marquetry (bonding of thin sections or layers of wood) was developed, the production of animal and fish glues refined, and other materials utilized. Egg based pastes were used to bond gold leaves and various natural ingredients such as blood, bone, hid, milk, cheese, vegetables, and grains were incorporated into glues. The Greeks began the use of slaked lime as mortar and the Romans furthered mortar development by mixing lime with volcanic ash and sand. This material, known as pozzolanic cement, was used in the construction of the Roman Colosseum and Pantheon.The Romans were also the first people known to have used tar and beeswax as caulk and sealant between the wooden planks of their boats and ships.