A seriously stretchy substance

The first civilizations to obtain rubber from trees were the Mayans and the Aztecs in South America. To get the sap from a rubber tree it’s as easy as making a thin diagonal cut to take off a bit of bark from which the latex sap drips out to be caught in a bucket. The latex sap will dry up after about six hours and it stops flowing but during this time approximately 3.7 litres of latex drips out. The process can be repeated again the following day. These early civilizations would allow the latex to dry and then make balls out of the substance. By dipping their feet into the gloopy substance then letting it dry some more and then repeating the process, they could shape shoes when the latex became thick enough. Holding the shoes over a fire would harden them up and made the rubber stronger.

Christopher Columbus brought back these rubber balls when he returned from his second voyage to the New World, and in the early 1700s, rubber samples and trees were brought back to Europe. At that time, rubber was still a novelty. Rubber did have its problems though as it was very soft and pliable like a pencil eraser. Joseph Priestley, a chemist, was the first to use rubber to erase lead marks. This is where the name ‘rubber’ comes from as he realised he could remove the lead marks by rubbing the material on them. For Silicone hoses, visit https://goodflexrubber.com/.

Natural rubber comes from this runny, milky white liquid called latex that oozes from certain plants when you cut into them. Even dandelions produce latex if you snap off their stems. There is no reason why we couldn’t make rubber from dandelions but we would need an awful lot of them! Although there are something like 200 plants in the world that produce latex, over 99 percent of the world’s natural rubber is made from the latex that comes from a tree species called Hevea brasiliensis, widely known as the rubber tree.

A seriously stretchy substance

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The latex from the rubber tree is about one third water and one third rubber particles held in a form known as a colloidal suspension. Natural rubber is a polymer of isoprene but to put it more simply, it’s made of many thousands of loosely joined molecules that make long, tangled chains. These chains of molecules can be pulled apart and untangled fairly easily, but they spring straight back together if you release them—and that’s what makes rubber elastic.

The rubber tree Hevea brasiliensis originally came from Brazil, from where it was introduced to such countries of the Far East as Malaysia, Indonesia, Burma, Cambodia, China, and Vietnam. Supplies of natural rubber were severely reduced during World War II just when they were needed most for military purposes. This had the effect of accelerating the development of synthetic rubbers, notably in Germany and the United States.

A seriously stretchy substance2

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Today, most natural rubber still comes from the Far East, while Russia, France, Germany, and the United States are among the world’s leading producers of synthetic rubber. The world’s largest single source of latex rubber is the Harbel Rubber Plantation near Monrovia in Liberia which was established in the 1920s by the Firestone tire company.

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