The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
Natural rubber, which is essentially cis-1,4-polyisoprene, exhibits elastic properties; its trans isomer on the other hand exhibits plastic properties. Like rubber, gutta percha is an extract from tropical trees, but unlike rubber it is hard and flexible at most ambient temperatures, softening at approximately 100°C.
Gutta-percha is derived from the trunk and leaves of the Malayan gutta tree (Palaquium gutta), which is grown on plantations. Trees are tapped or leaves are gathered, chopped, and soaked in boiling water. The gum is then recovered and packaged. Similar to gutta-percha is balata, the inferior quality latex of the South American bully tree (Mimusops balata). Both gutta-percha and balata are noted for their resistance to impact and embrittlement.
Gutta-percha was first exported from the Far East in 1838. English physicist and chemist Michael Faraday (1791-1867) soon noted that it was an electric insulator. This property, along with its ability to resist disintegration in salt-water, made it ideal for use as insulation for underwater telegraph cables, the first one being placed between England and France in 1850. A screw extruder was developed to coat the copper conductor, thus laying the foundations for today's plastics extrusion industry. Gutta percha also found early use as a molding material. It continues to be a component in some special adhesives, and both balata and gutta-percha are used in golf ball covers.