Editing Adhesive (section)

==History==
[[File:Animal glue liquid.jpg|thumbnail|left|Liquid animal glue]]

The earliest evidence of human adhesive use was discovered in central Italy when three stone implements were discovered with [[birch bark tar]] indications. The tools were dated to about 200,000 before present in the [[Middle Paleolithic]]. It is the earliest example of tar-[[axe|hafted]] stone tools.<ref name="Mazza"/>

An [[Experimental archaeology|experimental archeology]] study published in 2019 demonstrated how birch bark tar can be produced in an easier, more discoverable process. It involves directly burning birch bark under an overhanging rock surface in an open-air environment and collecting the tar that builds up on the rock.<ref>{{Cite journal|last1=Schmidt|first1= P.|last2=Blessing|first2= M.|last3= Rageot|first3= M.|last4= Iovita|first4= R.|last5= Pfleging|first5= J.|last6= Nickel|first6= K. G.|last7= Righetti|first7= L. |last8=Tennie|first8= C.|title=Birch tar extraction does not prove Neanderthal behavioral complexity|journal=PNAS|doi=10.1073/pnas.1911137116|pmid=31427508|volume=116|pmc=6731756|year=2019|issue=36|pages=17707–17711|bibcode=2019PNAS..11617707S |doi-access=free}}</ref>

Although sticky enough, plant-based, single-component adhesives can be 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 axe hafts were discovered covered with an adhesive composed of plant gum and red [[ochre]] (natural iron oxide) as adding ochre to plant gum produces a stronger product and protects the gum from disintegrating under wet conditions.<ref name="Wadley">{{cite journal |pmid=19433786 |date=Jun 2009|author1=Wadley, L |author2=Hodgskiss, T |author3=Grant, M |title=Implications for complex cognition from the hafting of tools with compound adhesives in the Middle Stone Age, South Africa |volume=106 |issue=24 |pages=9590–4 |issn=0027-8424 |doi=10.1073/pnas.0900957106 |journal=Proceedings of the National Academy of Sciences of the United States of America |pmc=2700998|bibcode = 2009PNAS..106.9590W |doi-access=free}}</ref> The ability to produce stronger adhesives allowed middle Stone Age humans to attach stone segments to sticks in greater variations, which led to the development of new tools.<ref>{{cite journal|last=Wadley|first=Lyn|title=Compound-Adhesive Manufacture as a Behavioral Proxy for Complex Cognition in the Middle Stone Age|journal=Current Anthropology|date=1 June 2010|volume=51|issue=s1|pages=S111–S119|doi=10.1086/649836|s2cid=56253913}}</ref> A study of material from [[Le Moustier]] indicates that Middle Paleolithic people, possibly [[Neanderthals]], used glue made from a mixture of ocher and [[bitumen]] to make hand grips for cutting and scraping stone tools.<ref>{{cite journal|first1=Patrick|last1= Schmidt|first2= Radu|last2= Iovita|first3= Armelle|last3= Charrié-Duhaut|first4= Gunther|last4= Möller|first5= Abay|last5= Namen|first6= Ewa|last6= Dutkiewicz|date=21 February 2024|url=https://www.researchgate.net/publication/378369816|title=Ochre-based compound adhesives at the Mousterian type-site document complex cognition and high investment|journal=Science Advances|volume=10|issue=8|pages=eadl0822 |doi=10.1126/sciadv.adl0822|pmid=38381827 |pmc=10881035|bibcode=2024SciA...10L.822S }}</ref>

More recent examples of adhesive use by prehistoric humans have 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 together with food found in broken clay pots repaired with tree resins.{{sfn|Ebnesajjad|2010|p=137}} Another investigation by archaeologists uncovered the use of [[bitumen|bituminous]] cements to fasten ivory eyeballs to statues in Babylonian temples dating to approximately 4000 BC.{{sfn|Mittal|Pizzi|2003|p=1}}

[[File:ReconstructedOetziAxe.jpg|thumb|upright|A reconstruction of [[Ötzi]]'s axe, which used pitch as an adhesive]]
In 2000, a paper revealed the discovery of a 5,200-year-old man nicknamed the "[[Tyrolean Iceman]]" or "Ötzi", who was preserved in a glacier near the Austria-Italy border. Several of his belongings were found with him including two arrows with flint arrowheads and a copper hatchet, each with evidence of organic glue used to connect the stone or metal parts to the wooden shafts. The glue was analyzed as [[pitch (resin)|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.<ref>Sauter F, Jordis U, Graf A, Werther W, Varmuza K. (2000). [http://www.arkat-usa.org/get-file.php?fileid=19868 Studies in organic archaeology I: identification of the prehistoric adhesive used by the "Tyrolean Iceman" to fix his weapons] {{Webarchive|url=https://web.archive.org/web/20110725014700/http://www.arkat-usa.org/get-file.php?fileid=19868 |date=25 July 2011 }}. ARKIVOC, 1:[5] 735–747</ref>

The first references to adhesives in literature appeared in approximately 2000 BC. Further historical records of adhesive use are found from the period spanning 1500–1000 BC. Artifacts from this period include paintings depicting wood gluing operations and a casket made of wood and glue in King [[Tutankhamun|Tutankhamun's]] tomb.{{sfn|Ebnesajjad|2010|p=137}} Other ancient Egyptian artifacts employ animal glue for bonding or lamination. Such lamination of wood for bows and furniture is thought to have extended their life and was accomplished using [[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.{{sfn|Mittal|Pizzi|2003|p=2}}

[[File:Molten beeswax.JPG|thumb|Beeswax|left]]
From AD 1 to 500 the Greeks and Romans made great contributions to the development of adhesives. [[Wood veneer]]ing and [[marquetry]] were developed, the production of animal and fish glues refined, and other materials utilized. Egg-based pastes were used to bond gold leaves, and incorporated various natural ingredients such as blood, bone, hide, milk, cheese, vegetables, and grains.{{sfn|Ebnesajjad|2010|p=137}} The Greeks began the use of [[slaked lime]] as mortar while the Romans furthered mortar development by mixing lime with volcanic ash and sand. This material, known as [[Pozzolana|pozzolanic cement]], was used in the construction of the Roman Colosseum and Pantheon.{{sfn|Mittal|Pizzi|2003|p=2}} 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.{{sfn|Ebnesajjad|2010|p=137}}

In Central Asia, the rise of the [[Mongols]] in approximately AD 1000 can be partially attributed to the good range and power of the bows of Genghis Khan's hordes. These bows were made of a bamboo core, with [[horn (anatomy)|horn]] on the belly (facing towards the archer) and [[tendon|sinew]] on the back, bound together with [[animal glue]].<ref>{{cite book |last1=Ashton |first1=J. E.|last2=Halpin|first2=John C. |last3=Petit|first3=P.H.|title=Primer on Composite Materials: Analysis |date=1969 |publisher=Technomic Publishing|oclc=27238 <!--DUPLICATE|isbn=9780877627548--> |location=Westport, Connecticut |isbn=0-87762-754-1}}</ref>

[[File:Casein glue preparation.jpg|framed|right|[[Casein glue]] preparation]]
In Europe, glue fell into disuse until the period AD 1500–1700.<ref>{{Cite book |last1=Stamm |first1=A.J. |title=Principles of Wood Science and Technology |last2=Kuenzi |first2=E.W. |last3=Kollmann |first3=Franz F.P. |publisher=Springer Berlin Heidelberg |year=2012 |isbn=9783642879319 |pages=1}}</ref> At this time, world-renowned cabinet and furniture makers such as [[Thomas Chippendale]] and [[Duncan Phyfe]] began to use adhesives to hold their products together.{{sfn|Ebnesajjad|2010|p=137}} In 1690, the first commercial glue plant was established in The Netherlands. This plant produced glues from animal hides.{{sfn|Mittal|Pizzi|2003|p=3}} In 1750, the first British glue patent was issued for fish glue. The following decades of the next century witnessed the manufacture of casein glues in German and Swiss factories.{{sfn|Ebnesajjad|2010|p=137}} In 1876, the first U.S. patent (number 183,024) was issued to the Ross brothers for the production of casein glue.{{sfn|Ebnesajjad|2010|p=137}}<ref>{{cite web|last=Ross|first=John|title=Improvement in Processes of Preparing Glue|url=http://patimg1.uspto.gov/.piw?Docid=00183024&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect2%3DPTO1%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%2Fnetahtml%2FPTO%2Fsearch-bool.html%2526r%3D1%2526f%3DG%2526l%3D50%2526d%3DPALL%2526S1%3D0183024.PN.%2526OS%3DPN%2F183024%2526RS%3DPN%2F183024&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page|publisher=United States Patent and Trademark Office|access-date=14 April 2013|author2=Charles Ross|date=10 October 1876|archive-date=14 January 2017|archive-url=https://web.archive.org/web/20170114040739/http://patimg1.uspto.gov/.piw?Docid=00183024&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect2%3DPTO1%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%2Fnetahtml%2FPTO%2Fsearch-bool.html%2526r%3D1%2526f%3DG%2526l%3D50%2526d%3DPALL%2526S1%3D0183024.PN.%2526OS%3DPN%2F183024%2526RS%3DPN%2F183024&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page|url-status=live}}</ref>

The first U.S. postage stamps used [[postage stamp gum|starch-based adhesives]] when issued in 1847. The first US patent (number 61,991) on dextrin (a starch derivative) adhesive was issued in 1867.{{sfn|Ebnesajjad|2010|p=137}}

Natural rubber was first used as material for adhesives in 1830,<ref>{{cite web|title=Bonding- An Ancient Art|url=http://www.adhesives.org/adhesives-sealants/fastening-bonding/history-of-bonding/bonding-an-ancient-art|work=Adhesives.org|publisher=Adhesives and Sealants Council|access-date=14 April 2013|archive-date=13 May 2013|archive-url=https://web.archive.org/web/20130513235141/http://www.adhesives.org/adhesives-sealants/fastening-bonding/history-of-bonding/bonding-an-ancient-art|url-status=dead}}</ref> which marked the starting point of the modern adhesive.<ref>{{Cite book|last=Wypych|first=George|title=Handbook of Adhesion Promoters|publisher=Elsevier|year=2018|isbn=978-1-927885-30-7|page=2}}</ref> In 1862, a British patent (number 3288) was issued for the plating of metal with brass by [[Electroplating|electrodeposition]] to obtain a stronger bond to rubber.{{sfn|Mittal|Pizzi|2003|p=3}} The development of the automobile and the need for rubber shock mounts required stronger and more durable bonds of rubber and metal. This spurred the development of cyclized rubber treated in strong acids. By 1927, this process was used to produce solvent-based thermoplastic [[rubber cement]]s for metal to rubber bonding.{{sfn|Mittal|Pizzi|2003|p=4}}

Natural rubber-based sticky adhesives were first used on a backing by Henry Day (US Patent 3,965) in 1845.{{sfn|Mittal|Pizzi|2003|p=4}} Later these kinds of adhesives were used in cloth backed surgical and electric tapes. By 1925, the pressure-sensitive tape industry was born.{{sfn|Kinloch|1987|page=2}}
Today, sticky notes, [[Scotch Tape]], and other tapes are examples of pressure-sensitive adhesives (PSA).<ref>{{Cite book|chapter-url=https://books.google.com/books?id=QZcbSr8MW98C&pg=PA499|title=Adhesion Science and Engineering: Surfaces, Chemistry and Applications|chapter=Chapter 13: Effect of rheology on PSA performance|author1=David J. Yarusso |editor1=A.V. Pocius |editor2=David A. Dillard|date=2002|publisher=Elsevier|isbn=978-0-08-052598-3|language=en}}</ref>

A key step in the development of synthetic plastics was the introduction of a [[thermoset plastic]] known as [[Bakelite]] phenolic in 1910.{{sfn|Ebnesajjad|2010|p=138}} Within two years, phenolic resin was applied to plywood as a coating varnish. In the early 1930s, phenolics gained importance as adhesive resins.{{sfn|Mittal|Pizzi|2003}}

The 1920s, 1930s, and 1940s witnessed great advances in the development and production of new plastics and resins due to the First and Second World Wars. These advances greatly improved the development of adhesives by allowing the use of newly developed materials that exhibited a variety of properties. With changing needs and ever evolving technology, the development of new synthetic adhesives continues to the present.{{sfn|Ebnesajjad|2010|p=138}} However, due to their low cost, natural adhesives are still more commonly used.{{sfn|Mittal|Pizzi|2003|p=10}}