Adhesive

== Description ==
Any non-metallic substance used to adhere one surface to another. Adhesives provide a wide selection of properties, solubility, tackiness, bonding time, and bonding strength. They can be used on nearly every kind of surface, such as wood, glass, metal, plastic, paper, fabric, and rubber. Adhesives are usually activated by water, solvents, pressure, heat, cold, or UV radiation. In some cases, surface treatment, abrasion, or an adhesion promoter may be needed to increase the strength or durability of the adhesive bond. Alternative binding techniques include sewing, mechanical fasteners and welding.
Adhesives may be classified as inorganic and organic adhesives: 
* Inorganic adhesives: water glass, plaster of Paris and portland cement. 
* Organic adhesives: animal (hide, bone, blood, casein, etc.), or vegetable (starch, gum, natural resin, etc.) or synthetic (Acrylic, Vinyl acetate, Cyanoacrylate, Epoxy, Silicone, etc.). 
Please see tables below for more information.
===Natural Adhesives===
Adhesive 	Examples 	Earliest use 	Composition 	Properties 	Applications
Albumin 	blood glue, egg glue 	Ancient times 	Protein-based made from blood or eggs 	Dark color, water-soluble powder that dries to a water-resistant film when activated with an alkali 	Plywood, masonry
Asphalt, Bitumen, Pitch, Tar	birch-bark tar, pitch, bitumen asphalt 	Ancient times 	Thick hydrocarbon-based liquids distilled from plants, wood or oil/coal deposits 	Typically dark and viscous, softens with heat, may evolve volatile compounds; water-repellant 	Boats, water-proofing
Casein 	Milk glue 	Ancient times 	Protein-based made from milk curd mixed with alkalis 	Water resistant; tensile strength eceeds most woods, non-toxic 	Woodworking, paper glue, fireproofing; glass bottle labels, gilding leather
Gelatin 	hide glue, rabbitskin glue, bone glue, fish glue, isinglass 	Ancient times 	Hydrolyzed collagen made from animal connective tissue and bones; hides are acid-treated, neturalized and repeatedly soaked	Hardens when cooled; may be slightly brittle; water-soluble 	Cabinetmaking, bookbinding, sizing fabrics
Keratin 	Hoof, horn 	Medieval or earlier	Partially hydrolyzed keratin; hooves or horns are fragmented then boiled and acidified. 	Hardens when cooled; does not become brittle 	Gluing and stiffening textiles, cabinetmaking, glass sealant
Mucilage 	agar, algin 	Ancient times 	Polar glycoprotesin and exopolysaccharid etracted from plants and seeds 	Viscous; soluble in water; edible; low bonding strength; sensitive to moisture, biodegradation and insects	postage stamps, labels on metal cans
Starch 	potato, rice, wheat; paste 	1847 	Starch granules swell in water for form a thick tacky gel upon cooling 	Soluble in cold water; become brittle with age; sensitive to moisture, biodegradation and insects 	Postage stamps, corrugated board, wallpaper
Tree resins 	balsam, dammar, gum arabic, mastic 	Ancient times 	Clear to translucent resins soluble in alcohol or turpentine; insoluble in water 	Darken with age 	Adhere jewels and beads, repair broken vessels
Wax 	insect wax (beeswax), plant wax (carnauba); mineral wax (paraffin)	Ancient times 	Long-chain hydrocarbons 	Becomes soft with heat 	Repair broken vessels; adhere pigments and inks
Rubber (natural, vulcanized)	Rubber cement; latex 	1830 to WWII 	Natural exudation obtained from plants, usually dissolved in solvent 	Solvent evaporates as it sets; latex may be an allergen; waterproof, discolors and cracks with time 	Used prior to synthetics
===Synthetic Adhesives===
Adhesive 	Examples 	Documented use	Composition 	Properties 	Applications
Acrylic (solvent-based) 	UHU All Purpose clear adhesive; Bostik All Purpose clear adhesive; 3M Brand PSA backing adhesive 	1940s 	Solvent cured acrylic resin often containing fillers like calcium carbonate, silica, and plasticizer. 	Clear, strong, fast setting glue that adhere to a wide range of materials 	
Acrylic latex 	Flugger; Weld-On acrylic cement; Trinseo 	1950s 	Butyl methacrylate, calcium carbonate, water 	inexpensive, fast-drying, and paintable; minimal shrinkage; used indoors 	Popular white glue commonly used in houses and schools
Arylic (pressure-sensitive)	most 3M brand tapers 	 	Methacrylate copolymers on polyethylene or polypropylene substrates; may contain tackifiers 	Low cost, thermally and oxidatively stable, optically clear. 	Used for plastic, paper, fabric, tapes and labels
Acrylonitrile polymers 	Acrylonitrile -butadiene,; acrylonitrile-butadiene Styrene (ABS); Styrene-Acrylonitrile (SAN); Nitrile rubber; Permabond	 	Solvent borne adhesive composed of acrylonitrile -polymer combinations along with solvent, tackifier and plasticizer 	Bonds vinyl, other elastomers and fabrics; provides good wear, oil and water resistance; may be used for under watr applications 	
Butyl rubber (synthetic) 	Butyl mastic, Buna-N rubber 	1950s 	Isobutylene-isoprene, talc calcium carbonate, mineral spirits, adhesion promoters 	Elastomeric with excellent peel strecngth but low shear strength; sticky and messy; more resistant to sunlight than natural rubbers; combustible; paintable 	Primarily used outdoors for metal and masonry joints that may expand and contract (gutters)
Cyanoacrylate 	Krazy glue, Superglue, Zap, ELFY, Eastman 910 	1941 	Thermosetting adhesive without heat or added catalyst 	Difficult to remove; degraded by UV light and alkalis 	Bonds metals to non-metals; used for glass, ceramic, and suturing skin
Epoxies 	Ablebond, Araldite AY103; Hxtal Nyl-1, Phiilyseal, CM Nond, Epotek, UHU 	1939 	A famil y of thermosetting resins that polymerize with themseolves or with co-reactants. Th reaction is exothermix 	High strength, good abrasion and chemical resistance, low water absorption; used for paint,coating, hard-plastics as well as adhesives; may cause allergic reactions 	Bonds wood, metal, glass , stone and some plastics
Ethylene vinyl acetate 	hot-melt glues, Elvax, A-C copolymer, Vinamul, Mowilith, Elvace 1874, Jade 834 	 	polyethylene mixed with about 10-40% vinyl acetate 	thermosetting polymer with rubber-like characteristics; soft, flexible material is waterproof, tough and stress-crack resistant; it has high cohesive strength and fast-setting speed 	Bond textiles, paper, glass; used as carpet backing adhesive
Phenol formaldehyde 	phenolic resin, resorcinol, Bakelite 	1907 	 	Temperature and UV resistant; off gases phenol and formaldehyde; water soluble until set; low cost; darkens in sunlight 	Used for laminating plywood especially for outdoor use
Urea formaldehyde 	 	1896 	Water-soluble resin 	Off-gases urea, ammonia and formaldehyde, thermosetting; degraded by hear, acids, alkalis 	Used for laminating plywood; particleboard
Polysulfide 	Neoprene, Thiokol 	1950s 	Any synthetic rubber vulcanized with sulfur (Neoprene, styrene-butadiene, polyisoprene). Some polusulfide elastomers are used with epoxies to provide flexibility 	will melt acrylic, polycarbonate, ABS and PVC plastics; can be used on nylon, epoxy, polyoxymethylene; may release sulfur; may contain PCBs; poor tensile strength; abrade easily; replaced in 1980s by silicone and urethane sealants	still used for chemically resistant tapes and gaskets in aircraft because of their vibration durability
Silicone 	Silastic, Clear Museum gel, Dowsil RTV 	1960s 	Silicone resin cured with moisture or peroxides; may contain fumed silica, calcium cabonate, ground quartz, carbon black, talc, plasticizers, acetone, methylene chloride. May be clear, white, or colored	water-repellent; long-life; wide temperature range; mold/mildew resistant; not paintable; poor adhesion; may release acetic acid or methanol on cure; may have residual curing compounds and silicone oils; may stain porous materials	Sealants are often used in outdoors settings; Pressure sensitive adhesives are used on skin for medical devices and drug delivery
Polyurethane 	Gorilla glue 	1937 	Available and one- or two-component adhesives, solvent -free; may be bulked with limestone and/or quartz 	shrink free; very durable; abrasion resistant; flexible at low temperatures; combustible producing toxic fumes; may release acetic acid on curing, aging, or deterioration; susceptiple to hydrolysis that may decrease adhesion 	Strong adhesive for metal and glue; laying carpets and wood floor board; may dissolve some plastics
Vinyl latex 	Vinyl emulsion; vinyl acrylic emulsion; white latex 	late 1960s 	Polyvinyl acetate as an emulsion in water usually with calcium carbonate, plasticizers and dispersing agents. Vinyl acrylic latex contains a co-polymer of vinyl acetate and butyl acrylate. 	inexpensive; high stability; water-resistant when dry; may be used as a liquid or solid (for heat sealing); may evolve trace acetic acid as it cures; 	Used for paper, textile, packaging, mounting photographs, laying carpets and floor tiles; also used as sealants and paints
== Synonyms and Related Terms ==
kleefstof (Ned.); adhésif (Fr.); colle (Fr.); Klebstoff (Deut.); adesivo (It.); adhesivo (Esp.); adesivo (Port.); adhesiv (Sven.); bindemedel (Sven.); mastic; cement; glue; mucilage; paste;
== Physical and Chemical Properties ==
== Resources and Citations ==
* AIC Conservation Wiki: Adhesives for Use Inside Exhibit Cases
* Irving Skeist, Handbook of Adhesives, Van Nostrand Reinhold Company, New York, 1977
* Matte Paint: Its history and technology, analysis, properties and conservation treatment, Eric Hansen, Sue Walston, Mitchell Bishop (ed.), J. Paul Getty Trust, Los Angeles, Vol. 30 of AATA, 1993
* Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
* Theodore J. Reinhart, 'Glossary of Terms', Engineered Plastics, ASM International, 1988
* Wikipedia: Adhesive (Accessed Feb. 2, 2006 and Feb 2023)
* G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 14
* Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
* The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998
* Multilingual Glossary for Art Librarians at http://www.ifla.org/VII/s30/pub/mgl.htm
* Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000
Category:Materials databaseCategory:MWGCategory:AdhesivesCategory:Comparisons