gutta-percha

enUK

gutta-percha

(gŭt`ə-pûr`chə), natural latexlatex,
emulsion of a polymer (e.g., rubber) in water (see colloid). Natural latexes are produced by a number of plants, are usually white in color, and often contain, in addition to rubber, various gums, oils, and waxes.
..... Click the link for more information. obtained from Palaquium gutta and several other evergreen trees of East Asia. The latex, collected by felling or girdling the tree, is allowed to coagulate and is then washed, purified, and molded into bricks for shipping. Like caoutchouccaoutchouc
, natural rubber obtained as a latex from various tropical plants, e.g., the Pará rubber tree. It is much more elastic than balata or gutta-percha. It is the most familiar and widely used of the natural rubbers.
..... Click the link for more information. , gutta-percha is a polyterpene, i.e., a polymer of isoprene (see rubberrubber,
any solid substance that upon vulcanization becomes elastic; the term includes natural rubber (caoutchouc) and synthetic rubber. The term elastomer is sometimes used to designate synthetic rubber only and is sometimes extended to include caoutchouc as well.
..... Click the link for more information. ), but, unlike caoutchouc, it is not very elastic; the reason for the difference is that the polymer molecules in gutta-percha have a trans structure, whereas those of caoutchouc have a cis structure (see isomerisomer
, in chemistry, one of two or more compounds having the same molecular formula but different structures (arrangements of atoms in the molecule). Isomerism is the occurrence of such compounds. Isomerism was first recognized by J. J. Berzelius in 1827.
..... Click the link for more information. ). Gutta-percha is an excellent nonconductor and is often employed in insulating marine and underground cables. It is also used for golf-ball coverings, surgical appliances, and adhesives.

Gutta-Percha

a metabolic product of gutta-percha-yielding plants. The main constituent of gutta-percha (up to 90 percent)—high-molecular-weight trans-polyisoprene (gut-ta) with the empirical formula (C₅H₈)_n—is an isomer of cis-polyisoprene, a hydrocarbon of natural rubber. The average molecular weight of gutta is about 50,000. Besides gutta, industrial gutta-percha contains resins, proteins, moisture, and other substances.

At room temperature, industrial gutta-percha is a solid skinlike substance that is white to yellowish-brown in color, with a density of 0.945–0.955 g/cm^3, and an index of refraction n_D²⁰ = 1.523. Gutta-percha is resistant to the action of acids, including hydrochloric and hydrofluoric acids. When heated (50°-100° C), gutta-percha softens and becomes plastic and soluble in aromatic and chlorinated hydrocarbons. Its most valuable properties are waterproofness (moisture absorption in two years does not exceed 0.2 percent) and high electric insulation properties (dielectric permeability, 2.6; specific volume electric resistance 10¹² ohm․m [10¹⁴ ohm •cm]). Like natural rubber, gutta-percha can be vulcanized with sulfur. The tensile strength of vulcanized gutta-percha is 17–30 meganewtons/m² (170–300 kilograms-force/cm²) and the relative elongation, 500–550 percent.

Gutta-percha is used mainly as insulation for underwater cables and in the manufacture of acid-resistant and adhesive substances. The use of gutta-percha is declining because it is being replaced by synthetic trans-polyisoprene, trans-polychloroprene (so-called synthetic gutta-percha), and some other synthetic polymers.

REFERENCES

Voinovskii, A. B. Guttapercha. Moscow-Leningrad, 1951.
Spravochnik rezinshchika. Materialy rezinovogo proizvodstva. Moscow, 1971. Page 251.

gutta-percha

[¦gəd·ə′pər·chə] (materials) A leathery, thermoplastic substance consisting of gutta hydrocarbon with some resin obtained from the latex of certain Malaysian sapotaceous trees; used as insulation for submarine cables, and in golf balls and other products.

gutta-percha

1. any of several tropical trees of the sapotaceous genera Palaquium and Payena, esp Palaquium gutta 2. a whitish rubber substance derived from the coagulated milky latex of any of these trees: used in electrical insulation and dentistry

gutta-percha

enUK

gutta-percha

[gut″ah-per´chah] the coagulated, dried, purified latex of trees of the genera Palaguium and Payena, most commonly Palaguium gutta; used in orthopedics for fracture splints, in surgery for temporary sealing of cavities, and in dentistry in the form of cones for filling root canals or sticks for sealing cavities over treatment.

gut·ta-per·cha

(gut'ă-pĕr'chă), The coagulated, purified, dried, milky juice of trees of the genera Palaquium (especially P. gutta and Payena (family Sapotaceae); a polyterpene-containing a trans isomer of rubber used as a filling material in dentistry, and in the manufacture of splints and electrical insulators; a solution is used as a substitute for collodion, as a protective, and to seal incised wounds. Compare: chicle, gutta. [Malay gatah, gum, + percha, the name of a tree]

gut·ta-per·cha

(gut'ă-pĕr'chă) The coagulated, purified, dried, milky juice of trees of the genera Palaguium and Payena (family Sapotaceae); used as a filling material in dentistry, especially to fill root canals in endodontics, and in the manufacture of splints and electrical insulators; a solution is used as a substitute for collodion, as a protective, and to seal incised wounds. Solid at room temperature and soft and pliable when heated. [Malay gatah, gum, + percha, the name of a tree]

gut·ta-per·cha

(gut'ă-pĕr'chă) The coagulated, dried, milky juice of trees of the genera Palaquium; polyterpene-containing a trans isomer of rubber used as a filling material in dentistry, and in the manufacture of splints and electrical insulators; a solution is used as a substitute for collodion, as a protective, and to seal incised wounds. [Malay gatah, gum, + percha, the name of a tree]

gutta-percha

gut·ta-per·cha

gutta-percha

gut•ta-per•cha

gutta-percha

gutta-percha

Gutta-Percha

REFERENCES

gutta-percha

gutta-percha

gutta-percha

gutta-percha

gut·ta-per·cha

gut·ta-per·cha

gut·ta-per·cha

gutta-percha

Words related to gutta-percha

noun a whitish rubber derived from the coagulated milky latex of gutta-percha trees

Related Words