Rubber is a general term for a variety of polymers that have elastic and flexible properties. Originally, rubber was meant strictly for naturally occurring polymer derived from rubber trees. Because natural rubber can degrade in sunlight, in the open air and in high heat conditions, synthetic rubbers were developed, which have similar flexibility and elasticity but more resistance to the elements.
Natural rubber is derived from the juice of the rubber tree and first found use in industry in the mid-1800s, cultivated from plantations in the rainforest. With the popularization of the automobile, Charles Goodyear used his process of vulcanization, which increased durability and strength, to make tires. However, because it is a natural substance, rubber is susceptible to degradation. Sunlight and ozone in the atmosphere can damage the polymer. Heat can warp or completely destroy natural rubber. In particular, natural rubber can dissolve or soften in the presence of oils and other solvents.
Neoprene is a synthetic chemical first developed by DuPont in 1930. It was originally developed because of the rubber shortage during the 1920s. It was designed for its resistance to oil and other solvents, but it has additional properties that make it superior to natural rubber. Neoprene is the brand name for the polymer polychloroprene, which is made by copolymerizing chloroprene with sulfur. Instead of sulfur, 2,3 dichloro 1,3-butadiene can also be used. The inclusion of chlorine in the polymer helps give it fire-resistant properties. Neoprene keeps its proprieties over a wide range of temperatures, from about -10 degrees Fahrenheit up to 200 degrees Fahrenheit.
Burning Natural Rubber
Because it is made of a hydrocarbon polymer, natural rubber easily burns. In terms of heat produced, natural rubber actually gives off roughly twice the energy as cellulose. Under high heat conditions, the substance begins to soften and lose its strength. Conversely, in cold conditions, natural rubber becomes brittle. Because natural rubber softens when heated, it can also degrade into gaseous elements, which can easily ignite and even explode at temperatures above 450 degrees Fahrenheit.
Burning of Neoprene
The chlorine within the Neoprene polymer makes it resistant to fire, but if a naked flame is brought next to it, Neoprene melts and burns. However, once the flame is removed, the fire subsides. Still, some tests in an actual fire simulation have shown Neoprene to burn. Like natural rubber, if brought to a high enough temperature (around 500 degrees Fahrenheit or higher), Neoprene decomposes into gaseous elements and can ignite or explode. Also like natural rubber, burning Neoprene produces gases and smoke. However, because it has chlorine in the polymer, the resulting gases can contain toxic materials like hydrogen chloride.
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