Rubber

Rubber is one of mans most used products and has been used for thousands of years. It is used by us everyday from cars to shoes. Rubber starts in the rubber tree and it ends up as synthetic rubber and nonsynthetic rubber. Rubber is a yellowish, amorphous material that is very elastic and it comes from the caoutchouc or more commonly known as the India rubber plant. Rubber does not look as we commonly know it to, until it has been vulcanized, pigmented, finished, and then modified into the product, like car tires for example. The rubber tree is not the only plant that produces rubber; you can obtain rubber from a variety of plants. The rubber tree is the most common way to get natural rubber and Styrene-butadiene rubber is the most common synthetic rubber. Rubber is natural substance and can be man made. It is used every day of our lives and for thousands of years by man, from toys to the tires on are cars.

Properties
Natural rubber is a polymer, like the material that comes from white sap called latex that can also be found in the rubber tree. Latex is 30% rubber and the rest is used for latex products. Rubber has a high molecular density; it also has a cis arrangement and spatial configuration, causing rubber have its elasticity. The vulcanization of rubber makes it more flexible and unvulcanized rubber is soluble in many hydrocarbons like benzene, toluene, gasoline, and lubricating oils. In general rubber is water resistant and is resistant to alkalis and weak acids. Synthetic rubber is resistant to oil, solvents, oxygen, ozone, weathering, certain chemicals, and changes in temperature. In order for natural rubber and synthetic rubber to meet the rubbery properties requirements, they must have three properties: long thread-like molecules, flexibility in the molecular chains to allow flexing and coiling, and some chemical or mechanical bond between molecules. Synthetic rubber is artificially made of a polymer, which has elastomers making it flexible. Rubber has many properties to it that makes it such a useful item and an important one as we use it for its flexibility and strength.

Uses
Rubber is used in many things for example: tires, rubber bands, hoses, and was used by the natives to waterproofs cloaks. It it also used for belts, gaskets, moulding, airplanes, trains, rollers, rainwear, balloons, balls, cushions, diving gear, chemical and medical tubing, lining of storage tanks, processing equipment, railroad tank cars, gloves, shoes, blankets, telephone housing, parts of radio sets, meters, electrical instruments, power transmission belting, mulch, adhesive, as a fiber, molding compound, and water lubricated bearings for wells.

How Rubber is Made
The process of making rubber begins at rubber tree plantations. At the plantations the workers will first tap the bark of the tree by cutting two small slits into the bark and the white sap, also known as latex, will drip out and be caught into collecting cups. The tree is tapped for up to two to three days and the latex will flow for up to three hours per day. Then the sap is taken and rolled into sheets and dried. Then it is shipped from the plantation to the companies. The sap is also kept as a liquid for shipping by adding ammonia in order to keep it from hardening. Then the liquid rubber is vulcanized. Vulcanization is a process that takes unstable latex, put it under high pressure and heat, then sulfur is added to make it a more stable product. Then at the factories, whether it is vulcanized or not it is put into molds to make the finished product.

History
The history of people using rubber can be traced all the way back to the Mayans. They used rubber for games, religious observances, and for tools. They made rubber balls for games, some weighed up to fifteen pounds. They used the sap from the rubber tree to secure ax heads to the sticks and they used it also as a medicine. They learned to mix the rubber sap and the juice from the morning glory vines to make it more springy and durable. Christopher Columbus on his second voyage found the natives playing with balls that were much more bouncy than the balls the sailors played on the ship with to pass the time. In 1736, several sheets of rubber were sent to France and all that saw it were fascinated by rubber. Then in 1738, a French astronomer was sent to Peru he brought back samples of the milky fluid that the indians had used it for lighting. Their name for this brightly burning fluid was cachuchu or caoutchouc. In 1791, an Englishman by the name of Samuel Peal discovered that a mixture of rubber and turpentine you could make paper water proof. The first rubber factory was established close to Paris, France in 1803. The first one in England was started by Thomas Hancock in 1820. Joseph Priestley also a English inventor found that you could use rubber as an eraser on paper. Around 1820 some American merchants sailing between Brazil and the New World got some shoes that were made out of rubber. Even though they were poorly made, the shoes were a huge hit. In 1823, Charles Macintosh discovered that you could use rubber to make water proof fabrics. In 1839, Charles Goodyear discovered by accident, that rubber and sulfur put together into a very high heat a stronger, more flexible rubber will come out. Most of the rubber came out of Brazil and other parts of South America until the 1870s when Sir Henry Wickham took some seeds to England and plantations also started up in Southeast Asia. Then at the beginning of the 20th century the automobile industry began caused the rubber boom. During the nineteen-thirties the rubber industry declined due to the Depression, but it picked back up again in the nineteen-forties. The rubber industry still continues today and rubber can be found in most everyday items.

Rubber Tree
The rubber tree is native to India, and Malaysia. It can also be found in South America, southeast Asia, and western Africa. Its scientific name is Ficus elastica and its more common names are the rubber tree, rubber plant, and the Indian rubber plant. It can grow up to 40 to 50 ft high and it can have multiple trunks due to their aerial roots. It has white sap that is in its leaves, stems, and wood. The sap can cause allergic reactions for some people if it has contact to the skin. The sap is used in the making of latex and other rubber materials. The sap has 30% rubber in it. It is often used as a houseplant. It has soft wood, high branches, and it can grow at a rapid rate. They like places that are humid and hot with lots of water. The rubber tree has a lifespan of ten to twenty years.