On this date in 1844, Charles Goodyear obtained his first rubber patent. 10 things you might not know about rubber.
Rubber comes from Hevea brasiliensis, a tall, softwood tree native to south America. In the wild this tree grows to a height of 34 metres (120 feet), but the trees cultivated for rubber production only reach about 24 metres (80 feet). The carbon they need to grow really tall is contained in the rubber which is harvested, and foliage is removed to make tapping easier.
Ancient people in South America knew about rubber 2,000 years ago. They used it to make soles for shoes and balls for ball games. The Mayans extracted white sap from rubber trees; the Olmecs who first created rubber balls. The Aztecs used rubber balls in a game called "ollama".
Rubber was brought to the attention of Europeans thanks to Christopher Columbus, who saw natives in Haiti playing with rubber balls in 1493.
It was 1735 before anyone made a scientific study of the stuff. This study was by Charles-Marie de La Condamine and François Fresneau of France.
The word rubber was coined by Joseph Priestley in 1770 when he found it could be used to rub out Pencil marks. It was Goodyear’s vulcanisation process which made rubber a desirable commodity.
The main chemical constituents of rubber are elastomers, or “elastic polymers,” large chainlike molecules that can be stretched to great lengths and yet recover their original shape. The first common elastomer was polyisoprene, from which natural rubber is made.
Rubber trees start producing latex when they're around six to seven years old and can be tapped for 20-30 years. During that time, a tree can produce 19 lbs of rubber each year. A tree will be tapped every couple of days, yielding approximately 50 grams (1.7 ounces) of latex. When it comes out of the tree, latex is white. Changes in colour occur when things are added. Tyres are black because carbon black has been added. Tapping is done by scoring the trunk of the tree at an angle of about 30 degrees, as high up as the tapper can reach. Subsequent cuts are made immediately below the previous one. Trees are often rested for a period after heavy tapping.
Synthetic rubber was first made in 1909 by Fritz Hofmann in Germany. In 1910, Russian scientist Sergei Lebedev made rubber from a colourless gas, butadiene, which came in handy during both World Wars when natural rubber was in short supply. Today, synthetic rubber has overtaken the use of natural rubber.
Hevea brasiliensis isn’t the only plant which produces latex; it’s merely the one that is best at it. One common plant which produces latex is the Dandelion. In Nazi Germany, research projects tried to use dandelions as a base for rubber production, but failed.
Thailand, Indonesia, Malaysia, China, India, the Philippines, Vietnam, Sri Lanka, Nigeria, Cote d'Ivoire, Cameroon, and Liberia are the world’s leading producers of natural rubber. 65% of the rubber produced is used by the automotive industry for mountings, gaskets, belts, hoses, and of course, tyres.
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