Gutta-percha

Source: Wikipedia, the free encyclopedia.
Palaquium gutta

Gutta-percha is a tree of the genus

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 "latex" and percha (perca) means "scrap" or "rag".

Description

Gutta-percha tree

P. gutta trees are 5–30 metres (20–100 ft) tall and up to 1 m (3 ft) in trunk diameter. The leaves are

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.

Chemistry

Chemical structure of gutta-percha[1]

Chemically, gutta-percha is a

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.[3]

Uses

Historic

Telegraph Construction and Maintenance Company in Greenwich
, London, circa 1865
Members of a Kayan tribe in Borneo harvesting the sap of a gutta-percha tree c. 1910

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.[4]

Scientifically classified in 1843, it was found to be a useful natural

unsustainable harvesting and collapse of supply.[8]

Electrical

Gutta-percha latex is biologically inert, resilient, and is a good electrical insulator with a high dielectric strength.[9]

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

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. [13]

Since about 1940, polyethylene has supplanted gutta-percha as an electrical insulator.[14]

Other

Lithograph depicting the caning of Charles Sumner with a cane made of gutta-percha
Boston, Massachusetts
)

In the mid-19th century, gutta-percha was used to make furniture, notably by the Gutta Percha Company, established in 1847.[5] 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.[15]

The "

guttie" golf ball (which had a solid gutta-percha core) revolutionized the game.[16] Gutta-percha was used to make "mourning" jewelry, because it was dark in color and could be easily molded into beads or other shapes.[17] 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.[18]

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.[19]

Gutta-percha was briefly used in bookbinding until the advent of vulcanization.[20]

The wood of many species is also valuable.[citation needed]

Today

Art

Gutta-percha is used as a resist in silk painting,[21][22] including some newer forms of batik.

Dentistry

Gutta-percha points used in dentistry

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

radiopacity
so that its presence and location can be verified in dental X-ray images.

Substitutes

Gutta-percha remained an industrial staple well into the 20th century, when it was gradually replaced with superior synthetic materials such as

balatá was often used in gutta-percha's place. The two materials are almost identical, and balatá is often called gutta-balatá.[citation needed
]

See also

References

  1. ISBN 8187224991
  2. ^
    ISBN 978-3-319-92387-1
    .
  3. ISBN 978-81-312-2181-5
    .
  4. ^ a b Harvey Wickes Felter and John Uri Lloyd. "Gutta-Percha-: An Untold Story. Prakesh et al. ~2001 Endodontology". King's American Dispensatory.
  5. ^ a b c Bill Burns, The Gutta Percha Company, atlantic-cable.com, accessed 6 October 2010.
  6. ^ Tully, John (2011). The Devil's Milk. NYU Press.
  7. ISBN 9781786303745
    .
  8. Project MUSE 367792
    .
  9. ISBN 978-93-5250-048-2
    .
  10. ^ The Atlantic Telegraph: Its History, from the Commencement of the Undertaking in 1854, to the Sailing of the "Great Eastern" in 1866. Bacon and Company. 1866. p. 108.
  11. ISBN 9780061985294
    .
  12. ^ Prescott, George Bartlett (1881). Electricity and the Electric Telegraph. D. Appleton. p. 956.
  13. ^ Curtis, H.L. Dielectric Constant, Power Factor and Resistivity of Rubber and Gutta_Percha (PDF) (Report). United States N.I.S.T.
  14. ISBN 978-1-78630-374-5
    .
  15. ^ Great Exhibition (1851) Reports by the Juries on the Subjects in the Thirty Classes Into which the Exhibition was Divided: Reports, classes XXIX, XXX. Vol. 4. London): Spicer Brothers. 1852. p. 1740.
  16. ISBN 978-0-7432-4976-8
    .
  17. ISBN 978-1-7346276-1-9
    .
  18. ISBN 978-0-313-08174-3
    – via Google Books.
  19. ^ McInnes, Paul (16 June 2022). "'Faster, sportier, fairer': are football's proposed new law trials a good idea?". The Guardian. Retrieved 1 October 2023.
  20. ISBN 978-1-56792-722-1
    .
  21. ISBN 0823048284
  22. ISBN 0715301578
  23. PMID 266025
    .

External links
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