Balata

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Balata drive belt in a power station around 1890

Balata is a natural, hard, horn- like material that is plastic and rubbery when exposed to heat . The gutta-percha-like substance is obtained by drying the milky sap of the South American balata tree . In contrast to natural rubber , the dry juice has a high resin content of around 40% and contains around 45% rubber. The resin is also partially or completely removed for various applications. Like rubber, balata can be vulcanized .

The rubbery part of the balata consists of trans - polyisoprenes (polyterpenes), in contrast to the cis - isomers of natural rubber, i.e. a geometrically different, otherwise identical molecule .

Similar products are gutta-percha and chicle , which come from the milky sap of other plant species. In these, the polyisoprenes of the rubbery part have a trans- or mixed configuration. The guayule rubber from the guayule ( Parthenium argentatum ) is also used to a greater extent, here the polyisoprenes are cis -configured.

Like gutta-percha, raw balata has the shape of leather-like, elastic plates, brownish on the outside and gray-white on the inside. It becomes soft and plastic at around 50 ° C and melts at around 150 ° C. It is more durable in air than gutta-percha because it does not oxidize as quickly.

Vulcanized balata was widely used in the past to make golf balls ; today ionomers are mostly used for this . It serves as a cheap substitute for gutta-percha as well as for the production of drive belts and shoe soles etc.

literature

Web links

Wiktionary: Balata  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ R. Hansel, O. Sticher, E. Steinegger: Pharmakognosie - Phytopharmazie. Volume 1, 6th edition, Springer, 1999, ISBN 978-3-662-09270-5 , p. 49.
  2. ^ Georg Frerichs, Georg Arends, Heinrich Zörnig: Hager's handbook of pharmaceutical practice. First volume, Springer, 1938, ISBN 978-3-642-88873-1 (reprint), p. 1416.
  3. ↑ Golf balls from 1600 to today on swisshickorygolf.ch, accessed on January 19, 2018.
  4. ↑ K. Kollmann, KH Bussmann, A. Dahl, G. Morchutt, B. Arp: Belt drives, chain drives, clutches: Lectures and contributions to the discussion at the “Drive Elements ” conference, Essen 1953 . Springer-Verlag, ISBN 978-3-663-02896-3 ( google.com ).