Rubber cement
Encyclopedia
Rubber cement is an adhesive
Adhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...

 made from elastic polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

s (typically latex) mixed in a solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...

 such as acetone
Acetone
Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...

, hexane
Hexane
Hexane is a hydrocarbon with the chemical formula C6H14; that is, an alkane with six carbon atoms.The term may refer to any of four other structural isomers with that formula, or to a mixture of them. In the IUPAC nomenclature, however, hexane is the unbranched isomer ; the other four structures...

, heptane
Heptane
n-Heptane is the straight-chain alkane with the chemical formula H3C5CH3 or C7H16. When used as a test fuel component in anti-knock test engines, a 100% heptane fuel is the zero point of the octane rating scale...

 or toluene
Toluene
Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3.It is an aromatic...

 to keep them fluid enough to be used. Water-based formulas
Copydex
Copydex is a common latex-based rubber cement in the UK. It can be easily recognised by its characteristic "fishy" odour. The founder of this product was Mr Jim Bean Sherwood, whose product has sold globally.-Uses:...

, often stabilised by ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

, are also available. This makes it part of the class of drying adhesives: as the solvents quickly evaporate, the "rubber
Rubber
Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...

" portion remains behind, forming a strong yet flexible bond. Often a small percentage of alcohol is added to the mix. Alcohol does not pose a problem, but acetone - a solvent widely used in nail polish removers - does irreparable damage on polished surfaces and many plastics.

Formula

The formula for rubber cement varies according to its targeted application. Those commonly used in office and art applications are usually non-vulcanizing and seldom differ between brands. However, they have been reformulated over time due to concerns over the toxicity of the chemicals involved, especially in regard to its use by children. Consumer-grade products generally no longer contain benzene because of its link to certain cancers. Instead, they tend to be based on less toxic solvents such as n-hexane and n-heptane.

Rubber cement based on n-heptane is very popular and ubiquitous in the United States, but is generally unknown and unavailable as a consumer product in the UK and some parts of Europe. A similar solvent based product called "Cow Gum" was common in the UK, but is no longer in production. Current solvent based options include Marabu-Fixogum and Platignum "Studio Gum" which are marketed in the UK and Europe. A water-based latex adhesive available in the UK is Copydex
Copydex
Copydex is a common latex-based rubber cement in the UK. It can be easily recognised by its characteristic "fishy" odour. The founder of this product was Mr Jim Bean Sherwood, whose product has sold globally.-Uses:...

. Marabu-Fixogum rubber cement and its thinner contain acetone as a solvent.

For tire patching, shoe repair, and other industrial applications, vulcanizing
Vulcanization
Vulcanization or vulcanisation is a chemical process for converting rubber or related polymers into more durable materials via the addition of sulfur or other equivalent "curatives." These additives modify the polymer by forming crosslinks between individual polymer chains. Vulcanized material is...

 formulas are preferred. These contain chemical additives which enable them to cross-link
Cross-link
Cross-links are bonds that link one polymer chain to another. They can be covalent bonds or ionic bonds. "Polymer chains" can refer to synthetic polymers or natural polymers . When the term "cross-linking" is used in the synthetic polymer science field, it usually refers to the use of...

 and harden into a tougher, more resilient form.

Usage

Rubber cement is favored in art applications where easy and damage-free removal of adhesive is desired. For example, rubber cement is used as the marking fluid in erasable pens. The rubber cement can be removed via the eraser up to 10 hours after application.

Cement formulations based on n-heptane and n-hexane will not shrink or swell paper fibers, thereby preventing wrinkles to the adhered surfaces. This makes them safe to use on most finished paper surfaces, unlike water-based glues such as PVA
Polyvinyl acetate
Polyvinyl acetate, PVA, PVAc, poly, is a rubbery synthetic polymer with the formula n. It belongs to the polyvinyl esters family with the general formula -[RCOOCHCH2]-...

 glue
Glue
This is a list of various types of glue. Historically, the term "glue" only referred to protein colloids prepared from animal flesh. The meaning has been extended to refer to any fluid adhesive....

s (e.g., white or Elmer's brand glue
Glue
This is a list of various types of glue. Historically, the term "glue" only referred to protein colloids prepared from animal flesh. The meaning has been extended to refer to any fluid adhesive....

).

Because rubber cements are designed to peel easily or rub off without damaging the paper or leaving any trace of adhesive behind, they are ideal for use in paste-up work where excess cement might need to be removed. It also does not become brittle as paste does. Rubber cement is not considered an archivally sound adhesive and will cause deterioration of photographs and papers over time.

Rubber cement is used in many magic tricks due to its property of sticking only to itself when dry as opposed to other objects as well.http://www.instructables.com/id/Make-a-Magic-bill-you-can-cut--and-restore-!-Amazi/.

VOC
Volatile organic compound
Volatile organic compounds are organic chemicals that have a high vapor pressure at ordinary, room-temperature conditions. Their high vapor pressure results from a low boiling point, which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the compound and...

-containing rubber cement is also a frequent gluing adhesive in table tennis, but is illegal under ITTF regulations, water-based rubber cement can still be used.

History

Rubber cement was invented by Paul Van Cleef in the early 1900s to be used in various applications in the Van Cleef Brothers factory in Chicago, Illinois.

Hazards

The solvents used in rubber cement present some hazards http://www.devcon.com/techinfo/14900.PDF, including flammability and potential for abuse as inhalants. Therefore, as with any adhesive, rubber cement should be used in an open area. Also, care needs be taken to avoid heat sources, as n-heptane and n-hexane are highly flammable. Rubber cement and rubber cement thinner (which is used to replace the solvent that evaporates from the container and to remove stains of glue) that contain acetone will damage polished surfaces and many plastics.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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