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.
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| 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] | Casein glue | 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 tissue and 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 |
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, 40–60 °C (104–140 °F) and heat conductivity means it can be moulded by hand. Can be used to mould itself. |
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 10 °C (50 °F). [6] | Needs to be clamped | Structural | Water-soluble until set, waterproof after. [6] | 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] |
Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation.
Cyanoacrylates are a family of strong fast-acting adhesives with industrial, medical, and household uses. They are derived from ethyl cyanoacrylate and related esters. The cyanoacrylate group in the monomer rapidly polymerizes in the presence of water to form long, strong chains.
Petrochemicals are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as maize, palm fruit or sugar cane.
Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also collectively called epoxy. The IUPAC name for an epoxide group is an oxirane.
Varnish is a clear transparent hard protective coating or film. It is not to be confused with wood stain. It usually has a yellowish shade due to the manufacturing process and materials used, but it may also be pigmented as desired. It is sold commercially in various shades.
Lamination is the technique/process of manufacturing a material in multiple layers, so that the composite material achieves improved strength, stability, sound insulation, appearance, or other properties from the use of the differing materials, such as plastic. A laminate is a layered object or material assembled using heat, pressure, welding, or adhesives. Various coating machines, machine presses and calendering equipment are used.
Araldite is a registered trademark of Huntsman Advanced Materials referring to their range of engineering and structural epoxy, acrylic, and polyurethane adhesives. Swiss manufacturers originally launched Araldite DIY adhesive products in 1946. The first batches of Araldite epoxy resins, for which the brand is best known, were made in Duxford, England in 1950.
In chemistry and biology, a cross-link is a bond or a short sequence of bonds that links one polymer chain to another. These links may take the form of covalent bonds or ionic bonds and the polymers can be either synthetic polymers or natural polymers.
Polyvinyl fluoride (PVF) or –(CH2CHF)n– is a polymer material mainly used in the flammability-lowering coatings of airplane interiors and photovoltaic module backsheets. It is also used in raincoats and metal sheeting. Polyvinyl fluoride is a thermoplastic fluoropolymer with a repeating vinyl fluoride unit, and it is structurally very similar to polyvinyl chloride.
A binder or binding agent is any material or substance that holds or draws other materials together to form a cohesive whole mechanically, chemically, by adhesion or cohesion.
Hot-melt adhesive (HMA), also known as hot glue, is a form of thermoplastic adhesive that is commonly sold as solid cylindrical sticks of various diameters designed to be applied using a hot glue gun. The gun uses a continuous-duty heating element to melt the plastic glue, which the user pushes through the gun either with a mechanical trigger mechanism on the gun, or with direct finger pressure. The glue squeezed out of the heated nozzle is initially hot enough to burn and even blister skin. The glue is sticky when hot, and solidifies in a few seconds to one minute. Hot-melt adhesives can also be applied by dipping or spraying, and are popular with hobbyists and crafters both for affixing and as an inexpensive alternative to resin casting.
An acrylate polymer is any of a group of polymers prepared from acrylate monomers. These plastics are noted for their transparency, resistance to breakage, and elasticity.
Wood glue is an adhesive used to tightly bond pieces of wood together. Many substances have been used as glues. Traditionally animal proteins like casein from milk or collagen from animal hides and bones were boiled down to make early glues. They worked by solidifying as they dried. Later, glues were made from plant starches like flour or potato starch. When combined with water and heated, the starch gelatinizes and forms a sticky paste as it dries. Plant-based glues were common for books and paper products, though they can break down more easily over time compared to animal-based glues. Examples of modern wood glues include polyvinyl acetate (PVA) and epoxy resins. Some resins used in producing composite wood products may contain formaldehyde. As of 2021, “the wood panel industry uses almost 95% of synthetic petroleum-derived thermosetting adhesives, mainly based on urea, phenol, and melamine, among others”.
Pressure-sensitive adhesive is a type of nonreactive adhesive which forms a bond when pressure is applied to bond the adhesive with a surface. No solvent, water, or heat is needed to activate the adhesive. It is used in pressure-sensitive tapes, labels, glue dots, stickers, sticky note pads, automobile trim, and a wide variety of other products.
Synthetic resins are industrially produced resins, typically viscous substances that convert into rigid polymers by the process of curing. In order to undergo curing, resins typically contain reactive end groups, such as acrylates or epoxides. Some synthetic resins have properties similar to natural plant resins, but many do not.
Conservation and restoration of ceramic objects is a process dedicated to the preservation and protection of objects of historical and personal value made from ceramic. Typically, this activity of conservation-restoration is undertaken by a conservator-restorer, especially when dealing with an object of cultural heritage. Ceramics are created from a production of coatings of inorganic, nonmetallic materials using heating and cooling to create a glaze. These coatings are often permanent and sustainable for utilitarian and decorative purposes. The cleaning, handling, storage, and in general treatment of ceramics is consistent with that of glass because they are made of similar oxygen-rich components, such as silicates. In conservation ceramics are broken down into three groups: unfired clay, earthenware or terracotta, and stoneware and porcelain.
Acrylonitrile styrene acrylate (ASA), also called acrylic styrene acrylonitrile, is an amorphous thermoplastic developed as an alternative to acrylonitrile butadiene styrene (ABS), that has improved weather resistance. It is an acrylate rubber-modified styrene acrylonitrile copolymer. It is used for general prototyping in 3D printing, where its UV resistance and mechanical properties make it an excellent material for use in fused filament fabrication printers, particularly for outdoor applications. ASA is also widely used in the automotive industry.
The conservation-restoration of panel paintings involves preventive and treatment measures taken by paintings conservators to slow deterioration, preserve, and repair damage. Panel paintings consist of a wood support, a ground, and an image layer. They are typically constructed of two or more panels joined together by crossbeam braces which can separate due to age and material instability caused by fluctuations in relative humidity and temperature. These factors compromise structural integrity and can lead to warping and paint flaking. Because wood is particularly susceptible to pest damage, an IPM plan and regulation of the conditions in storage and display are essential. Past treatments that have fallen out of favor because they can cause permanent damage include transfer of the painting onto a new support, planing, and heavy cradling. Today's conservators often have to remediate damage from previous restoration efforts. Modern conservation-restoration techniques favor minimal intervention that accommodates wood's natural tendency to react to environmental changes. Treatments may include applying flexible battens to minimize deformation or simply leaving distortions alone, instead focusing on preventive care to preserve the artwork in its original state.
Adhesive bonding is a joining technique used in the manufacture and repair of a wide range of products. Along with welding and soldering, adhesive bonding is one of the basic joining processes. In this technique, components are bonded together using adhesives. The broad range of types of adhesives available allows numerous materials to be bonded together in products as diverse as vehicles, mobile phones, personal care products, buildings, computers and medical devices.
Waterborne resins are sometimes called water-based resins. They are resins or polymeric resins that use water as the carrying medium as opposed to solvent or solvent-less. Resins are used in the production of coatings, adhesives, sealants, elastomers and composite materials. When the phrase waterborne resin is used, it usually describes all resins which have water as the main carrying solvent. The resin could be water-soluble, water reducible or water dispersed.