gutta-percha

gutta-percha , natural latex 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 caoutchouc , gutta-percha is a polyterpene, i.e., a polymer of isoprene (see rubber ), 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 isomer ). 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 (gut-ă-per-chă) n. the juice of an evergreen Malaysian tree, which is hard at room temperature but becomes soft and plastic when heated in hot water. On cooling gutta-percha will retain any shape imparted to it when hot; in dentistry it is used in root fillings.

gutta percha A latex, mainly of Sapotaceae but also of Eucommiaceae and some Celastraceae. Palaquium gutta, of Sumatra, Java, Malaya, and Borneo, is the main source. The latex is obtained by tapping the bark or by crushing the leaves in hot water. It is a better thermal and electrical insulator than rubber, almost non-elastic, and plastic above 82°C. It is now used only for temporary dental stoppings, but formerly it was used for submarine telephone cables and golf balls.