A few examples include styrene-butadiene rubber, polybutadiene rubber, and polyisoprene rubber. Since synthetic rubber is used in vastly different ways, its properties vary from form to form. But in general, there are a few distinct differences between natural and synthetic rubber that are important to note. Natural rubber is resistant to wear from chipping and tearing thanks to its high tensile strength.
Damages from heat, light, and ozone exposure, however, are more likely. Its tacky properties, especially toward steel cords, make it common in vehicle tires. Synthetic rubber is more resistant to abrasion than natural rubber. Its grease and oil resistance also makes it a popular choice for corrosive environments.
Synthetic rubber also has a strong resistance to heat and time—many varieties of synthetic rubber are even flame-resistant. This makes it a common choice for electric insulation. Synthetic rubber is also flexible, even in relatively low temperatures.
Synthetic rubber is more commonly used today because of its availability and ease of production, and in special circumstances that require its resistance to extreme temperatures and corrosion. To test the properties of your natural or synthetic rubber in a multitude of environments and situations, contact ACE Products and Consulting. There are countless other applications for different synthetic rubbers, ranging from chewing gum to sporting goods to belts and moldings.
Natural rubber is commonly used to produce high-performance vehicle tires that will need excellent tear strength, even at high temperatures caused by friction. Aircraft tires, heavy truck tires, and even sophisticated race car tires are often made from natural rubber. Silicone rubber, like rubber, is an elastomer. To tell the two apart, it is necessary to look at the atomic structure of the two substances. Synthetic rubber differs from natural rubber in that it is made by linking polymer molecules together in a laboratory.
Both natural and synthetic rubber need to undergo a series of processes to turn it into a usable product. These stages can be adapted slightly according to the intended use of the final product. Firstly, chemicals are added to the rubber to make it stable. Without this, the rubber would get brittle if it got cold or become sticky during high temperatures. Commonly, a carbon black filler is added to the rubber mix, to improve its strength and durability.
The rubber is then carefully mixed and allowed to cool, before being shaped. It can be shaped by pushing it into rollers, called calendering, or by squeezing it through holes to make hollow tubes, known as extrusion. In order to make rubber strong and durable, it finally goes through a heat-treatment phase known as vulcanisation.
This is where the rubber is cooked often with sulphur to create extra bonds or cross-links between the molecules of the rubber, so they don't easily fall apart. Charles Goodyear accidentally discovered this process, when he dropped some rubber onto a hot stove and noticed how the heat made the rubber harder and more durable.
Sometime later, he developed a revolutionary method for harvesting latex from the Hevea tree by continuous tapping. Tapping is the process of removing the latex from the tree.
The new plantations were more competitive in price, so from the end of the nineteenth century until the First World War, rubber collection from wild sources in tropical America declined tremendously. During the war, the supply of rubber was cut off.
The USA, Germany, and Russia started searching for alternative rubber sources, either natural or synthetic, since the Amazonian trees were not supplying enough rubber for their needs [ 3 ].
Several research programs started in these countries, but, after the war, the supply of rubber from Malaysian plantations started again and the effort to look for new rubber sources almost disappeared. In recent years, the search for alternative sources of rubber has begun again.
There are three main reasons for this:. First of all, the rubber trees are exposed to several diseases and since Asian rubber plantations started from only a handful of seeds, all the trees are genetically very similar. Less genetic variation means lower ability to fight against plant diseases. If one tree becomes sick, the illness can rapidly spread to the entire plantation. Today, the most important and dangerous disease that Hevea brasiliensis suffers from is called South American leaf blight disease.
This disease can cause the devastation of an entire plantation. It is still confined to the tropical Americas, but if it arrives in Asia, it could mean the end of the rubber plantations. Under natural conditions, rubber trees commonly grow with a lot of space between them. In nature, serious damage to Hevea from South American leaf blight is unusual, because the other kinds of trees growing in between the rubber trees are not susceptible to the disease and act as barriers.
But, on plantations where rubber trees grow very closely together, it can become lethal. Second of all, an important threat to the natural rubber market is the very competitive and fast-growing market for palm oil and its side products.
There is an increasing demand for both rubber and palm oil but, in Malaysia, the area in which Hevea brasiliensis is being grown is not decreasing, however, the area dedicated to grow oil palm is increasing. If the continuous growth of oil palm plantations does not stop, either the natural forest or the Hevea plantations will have to get smaller to make room for new crops of oil palms.
And last but not least, rubber tapping is a not well-paid job and it is difficult work. Young people tend to choose more attractive work, which could result in a shortage of skilled rubber tappers.
The latex proteins in rubber made from Hevea brasiliensis can produce severe allergies in certain people, even when they are exposed to very small amounts. The latex proteins are very difficult to separate from the rubber in the purification process. Since these allergies can be so dangerous, an alternative to rubber that does not contain these latex proteins would be advantageous. The conditions needed to grow these rubber trees are very specific and only occur in certain areas in the world.
Goodyear sent his products to Europe in hopes of enticing investors. English inventor and rubber pioneer Thomas Hancock was enticed. He figured out Goodyear's vulcanization process and hastily applied for an English patent before Goodyear. Ultimately, many other businesses infringed on Goodyear's patents, and he spent much of his fortune on litigation or on rubber experiments. He died impoverished in He'd probably be happy to know that the Goodyear Tire and Rubber Company was named in his honor.
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