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Gutta-percha is a tree of the genus Palaquium in the family Sapotaceae. The name also refers to the rigid, naturally biologically inert, resilient, electrically nonconductive, thermoplastic latex derived from the tree, particularly from Palaquium gutta ; it is a polymer of isoprene which forms a rubber-like elastomer.
The word "gutta-percha" comes from the plant's name in Malay: getah translates as 'sticky gum' and pertja (perca) is the name of a less-sought-after gutta tree. The western term therefore is likely a derivative amalgamation of the original native names. [1]
Palaquium gutta trees are 5–30 metres (20–100 ft) tall and up to 1 m (3 ft) in trunk diameter. The leaves are evergreen, alternate or spirally arranged, simple, entire, 8–25 cm (3–10 in) long, glossy green above, and often yellow or glaucous below. The flowers are produced in small clusters along the stems, each flower with a white corolla with four to seven (mostly six) acute lobes. The fruit is an ovoid 3–7 cm (1–3 in) berry, containing one to four seeds; in many species, the fruit is edible.
In Australia, gutta-percha is a common name specifically used for the euphorbiaceous tree Excoecaria parvifolia, which yields an aromatic, heavy, dark-brown timber.
Chemically, gutta-percha is a polyterpene, a polymer of isoprene, or polyisoprene, specifically (trans-1,4-polyisoprene). [3] The cis structure of polyisoprene is the common latex elastomer. [3] While latex rubbers are amorphous in molecular structure, gutta-percha (the trans structure) crystallizes, leading to a more rigid material. It exists in alpha and beta forms, with the alpha form being brittle at room temperature. [4]
Long before gutta-percha was introduced into the Western world, it was used in a less-processed form by the natives of the Malaysian archipelago for making knife handles, walking sticks, and other purposes. The first European to study this material was John Tradescant, who collected it in the far east in 1656. He named this material "Mazer wood". William Montgomerie, a medical officer in imperial service, introduced gutta-percha into practical use in the West. He was the first to appreciate the potential of this material in medicine, and he was awarded the gold medal by the Royal Society of Arts, London in 1843. [5]
Scientifically classified in 1843, it was found to be a useful natural thermoplastic. In 1851, 30,000 long cwt (1,500 t) of gutta-percha was imported into Britain. [6] During the second half of the 19th century, gutta-percha was used for many domestic and industrial purposes, [7] and it became a household word. Gutta-percha was particularly important for the manufacture of underwater telegraph cables. [6] Compared to rubber, it does not degrade in seawater, is not damaged by marine life, and maintains good electrical insulation. [8] These properties, along with its mouldability and flexibility made it ideal for the purpose, with no other material to match it in the 19th century. [9] The use in electrical cables generated a huge demand which led to unsustainable harvesting and collapse of supply. [10]
Gutta-percha latex is biologically inert, resilient, and is a good electrical insulator with a high dielectric strength. [8]
Michael Faraday discovered its value as an insulator soon after the introduction of the material to Britain in 1843. [11] Allowing this fluid to evaporate and coagulate in the sun produced a latex which could be made flexible again with hot water, but which did not become brittle, unlike rubber prior to the discovery of vulcanization.[ citation needed ]
By 1845, telegraph wires insulated with gutta-percha were being manufactured in the UK. It served as the insulating material for early undersea telegraph cables, including the first transatlantic telegraph cable. [12] The material was a major constituent of Chatterton's compound [13] used as an insulating sealant for telegraph and other electrical cables.[ citation needed ]
The dielectric constant of dried gutta-percha ranges from 2.56 to 3.01. Resistivity of dried gutta-percha ranges from 25×1014 to 370×1014 Ω⋅cm. [14]
Since about 1940, polyethylene has supplanted gutta-percha as an electrical insulator. [15]
In the mid-19th century, gutta-percha was used to make furniture, notably by the Gutta Percha Company, established in 1847. [6] Several of these ornate, revival-style pieces were shown at the 1851 Great Exhibition in Hyde Park, London. The company also made a range of utensils. [16]
The "guttie" golf ball (which had a solid gutta-percha core) revolutionized the game. [17] Gutta-percha was used to make "mourning" jewelry, because it was dark in color and could be easily molded into beads or other shapes. [18] Pistol hand grips and rifle shoulder pads were also made from gutta-percha, since it was hard and durable, though it fell into disuse when synthetic plastics such as Bakelite became available.
Gutta-percha was used in canes and walking sticks. In 1856, United States Representative Preston Brooks used a cane made of gutta-percha as a weapon in his attack on Senator Charles Sumner. [19]
In the 1860s, gutta-percha was used to reinforce the soles of football players' boots before it was banned by The Football Association in the first codified set of rules in 1863. [20]
Gutta-percha was briefly used in bookbinding until the advent of vulcanization. [21]
The wood of many species is also valuable.[ citation needed ]
Gutta-percha is used as a resist in silk painting, [22] [23] including some newer forms of batik.
The same bioinertness that made it suitable for marine cables also means it does not readily react within the human body. It is used in a variety of surgical devices and during root canal therapy. It is the predominant material used to obturate, or fill, the empty space inside the root of a tooth after it has undergone endodontic therapy. Its physical and chemical properties, including its inertness and biocompatibility, melting point, [24] ductility, and malleability, make it important in endodontics, [5] e.g., as gutta-percha points. Zinc oxide is added to reduce brittleness and improve plasticity. Barium sulfate is added to provide radiopacity so that its presence and location can be verified in dental X-ray images.
Gutta-percha remained an industrial staple well into the 20th century, when it was gradually replaced with superior synthetic materials, such as Bakelite.
A similar and cheaper natural material called balatá was often used in gutta-percha's place. The two materials are almost identical, and balatá is often called gutta-balatá.[ citation needed ]
An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials—semiconductors and conductors—conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are non-metals.
Rubber, also called India rubber, latex, Amazonian rubber, caucho, or caoutchouc, as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, Indonesia, and Cambodia are four of the leading rubber producers.
An electrical cable is an assembly of one or more wires running side by side or bundled, which is used as an electrical conductor to carry electric current.
Chatterton’s compound is an adhesive waterproof insulating compound that was used in early submarine telegraph cables. It was patented in 1859 by John Chatterton and Willoughby Smith.
Manilkara bidentata is a species of Manilkara native to a large area of northern South America, Central America and the Caribbean. Common names include bulletwood, balatá, ausubo, massaranduba, quinilla, and (ambiguously) "cow-tree".
An elastomer is a polymer with viscoelasticity and with weak intermolecular forces, generally low Young's modulus (E) and high failure strain compared with other materials. The term, a portmanteau of elastic polymer, is often used interchangeably with rubber, although the latter is preferred when referring to vulcanisates. Each of the monomers which link to form the polymer is usually a compound of several elements among carbon, hydrogen, oxygen and silicon. Elastomers are amorphous polymers maintained above their glass transition temperature, so that considerable molecular reconformation is feasible without breaking of covalent bonds. At ambient temperatures, such rubbers are thus relatively compliant and deformable.
In electronics, electrical breakdown or dielectric breakdown is a process that occurs when an electrically insulating material, subjected to a high enough voltage, suddenly becomes a conductor and current flows through it. All insulating materials undergo breakdown when the electric field caused by an applied voltage exceeds the material's dielectric strength. The voltage at which a given insulating object becomes conductive is called its breakdown voltage and, in addition to its dielectric strength, depends on its size and shape, and the location on the object at which the voltage is applied. Under sufficient voltage, electrical breakdown can occur within solids, liquids, or gases. However, the specific breakdown mechanisms are different for each kind of dielectric medium.
A stopper, bung, or cork is a cylindrical or conical closure used to seal a container, such as a bottle, tube, or barrel.
Eucommia ulmoides is a species of small tree native to China. It belongs to the monotypic family Eucommiaceae. It is considered vulnerable in the wild, but is widely cultivated in China for its bark and is highly valued in herbology such as traditional Chinese medicine.
Polyisoprene is strictly speaking a collective name for polymers that are produced by polymerization of isoprene. In practice polyisoprene is commonly used to refer to synthetic cis-1,4-polyisoprene, made by the industrial polymerisation of isoprene. Natural forms of polyisoprene are also used in substantial quantities, the most important being "natural rubber", which is derived from the sap of trees. Both synthetic polyisoprene and natural rubber are highly elastic and consequently used to make tires and a variety of other applications.
A post and core crown is a type of dental restoration required where there is an inadequate amount of sound tooth tissue remaining to retain a conventional crown. A post is cemented into a prepared root canal, which retains a core restoration, which retains the final crown.
A liquid dielectric is a dielectric material in liquid state. Its main purpose is to prevent or rapidly quench electric discharges. Dielectric liquids are used as electrical insulators in high voltage applications, e.g. transformers, capacitors, high voltage cables, and switchgear. Its function is to provide electrical insulation, suppress corona and arcing, and to serve as a coolant.
Manilkara huberi, also known as masaranduba, níspero, and sapotilla, is a fruit bearing plant of the genus Manilkara of the family Sapotaceae.
Palaquium gutta is a tree in the family Sapotaceae. The specific epithet gutta is from the Malay word getah meaning 'sap or latex'.
Biofilling, also known as the orthograde canal grafting technique or 4D sealing, is an endodontic root canal obturation technique with a Bioceramic material after root canal preparation and enlargement procedure.
William Montgomerie (1797–1856) was a Scottish military doctor with the East India Company, and later head of the medical department at Singapore. He is best known for promoting the use of gutta-percha in Europe. This material was an important natural rubber that made submarine telegraph cables possible. Montgomerie was involved in spice cultivation as head of the Singapore botanical experimental gardens and at his personal estate in Singapore. The latter never became economically viable, but he received a Society of Arts gold medal for nutmeg cultivation. He was also responsible for building the first lunatic asylum in Singapore. Montgomerie died at Barrackpore in India a few years after taking part in the Second Anglo-Burmese War as Superintendent Surgeon.
The Submarine Telegraph Company was a British company which laid and operated submarine telegraph cables.
The Gutta Percha Company was an English company formed in 1845 to make a variety of products from the recently introduced natural rubber gutta-percha. Unlike other natural rubbers, this material was thermoplastic allowing it to be easily moulded. Nothing else like it was available to manufacturing until well into the twentieth century when synthetic plastics were developed.
The British and Irish Magnetic Telegraph Company was a provider of telegraph services and infrastructure. It was founded in 1850 by John Brett. The Magnetic became the principal competitor to the largest telegraph company in the United Kingdom, Electric Telegraph Company, and became the leading company in Ireland. The two companies dominated the market until the telegraph was nationalised in 1870.
Brosimum parinarioides, also called leite de amapá, is an evergreen tree which grows in the semi-arid to humid tropical lowlands of South America. It can reach a height of up to 32 m.
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