rubber. [3] There are advantages and disadvantages of both synthetic and natural
rubber.
Results
Hevea trees are native to the Amazon region, but were brought to Asia, which is now the
largest producer of natural rubber. [1] Natural rubber is obtained by a process called tapping. [2] A
knife is used to make a shallow cut in the tree to allow latex to flow freely and be collected in a
cup.[2] A single tapping yields about 50 grams of rubber and usually occurs once every two days.
[2] Natural rubber can be produced at a rate of about 1 ton of rubber per acre per year. [2]
Natural rubber is the linear chain polymer, cis-l,4-polyisoprene. The polymer is made up
of regular repeating 2-metbyl-l,3-diene. The image to the
left shows the molecular composition of natural rubber.
The polymer begins as isopentenyl pyrophosphate and
becomes cis-polyisoprene through condensation via the
enzyme, rubber transferase. Refer to the image below for
the complete biosynthesis process.
Styrene-butadiene rubber (SBR) is the
most common synthetic rubber. It was
developed during World War I and II by
American and European scientists with the
purpose of resolving a shortage of natural
rubber. It was originally patented in 1933 by the
German chemists, Eduard Tschunkur and Walter
Bock.