Chemical Makeup
Latex is the polymer cis-1,4-polyisoprene) – with a molecular weight of 100,000 to 1,000,000. Typically, a small percentage (up to 5% of dry mass) of other materials, such as proteins, fatty acids, resins and inorganic materials (salts) are found in natural rubber. Polyisoprene can also be created synthetically, producing what is sometimes referred to as "synthetic natural rubber", but the synthetic and natural routes are completely different
Some natural rubber sources called gutta-percha are composed of trans-1,4-polyisoprene, a structural isomer that has similar, but not identical, properties.
Natural rubber is an elastomer and a thermoplastic. Once the rubber is vulcanized, it will turn into a thermoset. Most rubber in everyday use is vulcanized to a point where it shares properties of both; i.e., if it is heated and cooled, it is degraded but not destroyed.
The final properties of a rubber item depend not just on the polymer, but also on modifiers and fillers like carbon black, factice, whiting, and a host of others.
Read more about this topic: Rubber
Famous quotes containing the words chemical and/or makeup:
“We are close to dead. There are faces and bodies like gorged maggots on the dance floor, on the highway, in the city, in the stadium; they are a host of chemical machines who swallow the product of chemical factories, aspirin, preservatives, stimulant, relaxant, and breathe out their chemical wastes into a polluted air. The sense of a long last night over civilization is back again.”
—Norman Mailer (b. 1923)
“In the middle of the next century, when the literary establishment will reflect the multicultural makeup of this country and not be dominated by assimiliationists with similar tastes, from similar backgrounds, and of similar pretensions, Langston Hughes will be to the twentieth century what Walt Whitman was to the nineteenth.”
—Ishmael Reed (b. 1938)