There are many adhesive substances that are considered or commonly referred to as glue. Historically, the term only referred to protein colloids prepared from animal flesh. The meaning has been extended to refer to any fluid adhesive.
Type | Subtypes | Source(s) | Manufacture | Chemistry | Volatiles | Safety | Properties | Shelf life | Working time | Setting | Strength | Solvents | Uses | Date | ||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Roasted hydrocarbons | Tar, pitch, and asphalt/ bitumen | Made from plants (especially wood) or fossil hydrocarbons | natural or artificial destructive distillation | Hydrocarbon goo of no specific chemical formula | Emits Volatile organic compounds, especially when heated | health effects understudied (see Asphalt#Health and safety) | dark, viscous, more flexible when heated | Indefinite, may stiffen | Indefinite | Reversibly becomes more flexible and fluid when heated | water-repellant, | Sealant, hafting | prehistoric | |||
Mixed-protein glues[1] | align=center | Casein glue | align=center | Milk, limestone and brine | Milk curd is mixed with alkalis | non-toxic (preservatives excepted) | Once wet, 6–7 hours. | ~4 hours for softwood, 8 for hardwood; must be under pressure for >0.5-2 hrs | tensile strength exceeds most woods, 2,200-3,00 pounds per square inch | water-resistant, depending on alkalis used | Woodworking, paper glue, fireproof laminates | Medieval or earlier | ||||
Soybean glue | As for casein glue, but using soy protein | Soy protein is mixed with alkalis | ||||||||||||||
Albumin glues (blood glues and egg albumin adhesive, EAA) | blood (serum albumin) or eggs | prehistoric | ||||||||||||||
Gelatin glues | hide glue, including rabbit-skin glue;bone glue, and fish glue including isinglass | Animal connective tissueand bones | hides are acid-treated, neutralized, and repeatedly soaked; the soaking-water is dried into chips | hydrolyzed collagen | Until it cools | Thermoplastic. Somewhat brittle when set | Water-soluble | Cabinetmaking, bookbinding, lutherie, glue-size | ||||||||
Keratin glues | Hoof glue and horn glue | hooves of ungulates, animal horns | Hooves or horns are fragmented, boiled into goo, and acidified | partially- hydrolyzed keratin | Until it cools | Thermoplastic. Hardens as it cools, but does not become brittle | Gluing and stiffening textiles, cabinetmaking, glass sealant | |||||||||
Fibrin glue | human fibrinogen and human thrombin | when two parts are mixed, they form fibrin | 10–60 seconds | converts to fibrin | Medicine | |||||||||||
Waxes | Beeswax | made by insects | ||||||||||||||
Starch glues | potato starch, rice glue, wheatpaste | starches (plant energy-storage chemicals) | Starch may be purified before being mixed with water; leaving gluten in makes a more permanent bond | |||||||||||||
Dextrin glues | British gum, Coccoina | usually derived from potato starch | mid-19th century | |||||||||||||
Polysaccharide glues | mucilage, agar, algin | |||||||||||||||
Tree gums/resins | Balsam (fir) resins, such as Canada balsam, Dammar gum, Gum Arabic (also called acacia gum), Mastic | |||||||||||||||
Latex rubber cement(cow gum) | latex, a coagulating plant fluid, also made synthetically | latex is dissolved in an organic solvent | organic solvent evaporates as it sets | solvent may be hazardous; latex is an allergen | ||||||||||||
Methyl cellulose | cellulose, a plant structural material, and methyl chloride | heating cellulose with an alkali and reacting it with methyl chloride |
Solvent adhesives temporarily dissolve the substance they are gluing, and bond by solvent-welding material together with the re-solidified material.
Type | Subtypes | Source(s) | Manufacture | Chemistry | Volatiles | Safety | Properties | Shelf life | Working time | Setting | Strength | Solvents | Uses | Date | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Ketones | Acetone | dissolves ABS plastic | it is volatile | ||||||||||||
Polystyrene cement/Butanone/methyl ethyl ketone (MEK) | dissolves polystyrene | it is volatile | Vapour is heavier-than-air and explosive. Toxic, neuropsychological effects. Rapidly absorbed through undamaged skin and lungs. Produces toxic ozone.[2] | ||||||||||||
Dichloromethane | Dissolves:
| it is volatile, boiling at 39.6°C (103.3°F; 312.8K) | Will also glue acrylic to wood.[3] Clear, waterproof, exterior grades exist.[4] | 24 hours to set fully.[5] |
Type | Subtypes | Source(s) | Manufacture | Chemistry | Volatiles | Safety | Properties | Shelf life | Working time | Setting | Strength | Solvents | Uses | Date |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Acrylonitrile | synthetic monomer | |||||||||||||
Cyanoacrylate ("Superglue", "Krazy Glue") | synthetic monomer | |||||||||||||
Methyl acrylate ("acrylic") | synthetic monomer |
See main article: thermoplastic polymer and Hot-melt adhesive. Thermoplastic glues including hot-melt adhesives cure reversibly as they cool, like the gelatin and keratin glues listed above. They frequently don't emit volatiles unless overheated.
Type | Subtypes | Source(s) | Manufacture | Chemistry | Volatiles | Safety | Properties | Shelf life | Setting | Strength | Solvents | Uses | Date |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Ethylene-vinyl acetate | synthetic | polyethylene mixed with about 11% vinyl acetate | |||||||||||
Polyolefins | (polyethylene, polypropylene, etc.) | synthetic | thermosetting | ||||||||||
Polyamides | synthetic | ||||||||||||
Polyesters | synthetic | ||||||||||||
Polyurethanes | synthetic | ||||||||||||
Polycaprolactone | synthetic | biodegradable | very low melting temperature, and heat conductivity means it can be moulded by hand. Can be used to mould itself. |
See main article: thermosetting polymer. Thermosetting glues or thermosets cure irreversibly by polymerization. The polymerization can be triggered by heat or other radiation, or high pressure or a catalyst/hardener may be added.
Type | Subtypes | Source(s) | Manufacture | Chemistry | Volatiles | Safety | Properties | Shelf life | Working time | Setting | Strength | Solvents | Uses | Date |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Phenol formaldehyde resins (PF), also called phenolic resins | Resorcinol glue, Para tertiary butylphenol formaldehyde resin | synthetic | resorcinol or similar is mixed with phenol to make a resin; cured by adding formaldehyde | offgasses phenol and formeldehyde | phenol and formeldehyde are toxic, PTBPF causes contact allergies | Temperature-, UV-, and microbe-resistant. No gap-filling; joint must fit tightly. Brown in colour, sands off.[6] | A few years, unmixed. | Temperature-dependent. Will not cure at temperatures below 10C. | Needs to be clamped | Structural | Water-soluble until set, waterproof after. | laminating plywood, especially for exterior use; woodworking | ||
Urea-formaldehyde glue | synthetic | urea and formaldehyde | offgasses urea and formeldehyde | formeldehyde is toxic, urea is an irritant | thermosetting | |||||||||
Polysulfides | synthetic | Will melt acrylic, polycarbonate, ABS and PVC plastic. Can be used to glue nylon, epoxy, and polyoxymethylene.[7] |