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Polyisoprene
Polyisoprene is, strictly speaking, a collective name for polymers that are produced by polymerization of isoprene. In practice polyisoprene is commonly used to refer to synthetic ''cis''-1,4-polyisoprene, made by the industrial polymerisation of isoprene. Natural forms of polyisoprene are also used in substantial quantities, the most important being "natural rubber" (mostly ''cis''-1,4-polyisoprene), which is derived from the sap of trees. Both synthetic polyisoprene and natural rubber are highly elastic and consequently used to make tires and a variety of other applications. The ''trans'' isomer, which is much harder than the ''cis'' isomer, has also seen significant use in the past. It too has been synthesised and extracted from plant sap, the latter resin being known as gutta-percha. These were widely used as an electrical insulator and as components of golf balls. Annual worldwide production of synthetic polyisoprene was 13 million tons in 2007 and 16 million tons in 202 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Rubber
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Types of polyisoprene that are used as natural rubbers are classified as elastomers. Currently, rubber is harvested mainly in the form of the latex from the Hevea brasiliensis, Pará rubber tree (''Hevea brasiliensis'') or others. The latex is a sticky, milky and white colloid drawn off by making incisions in the bark and collecting the fluid in vessels in a process called "tapping". Manufacturers refine this latex into the rubber that is ready for commercial processing. Natural rubber is used extensively in many applications and products, either alone or in combination with other materials. In most of its useful forms, it has a large stretch ratio and high resilience and also is buoyant and water-proof. Industrial demand for rubber-like materials began to out ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condom
A condom is a sheath-shaped Barrier contraception, barrier device used during sexual intercourse to reduce the probability of pregnancy or a Sexually transmitted disease, sexually transmitted infection (STI). There are both external condoms, also called male condoms, and Internal condom, internal (female) condoms. The external condom is rolled onto an erect penis before intercourse and works by forming a physical barrier which limits skin-to-skin contact, exposure to Bodily Fluids, fluids, and blocks semen from entering the body of a sexual partner. External condoms are typically made from latex and, less commonly, from polyurethane, polyisoprene, or lamb intestine. External condoms have the advantages of ease of use, ease of access, and few side effects. Individuals with latex allergy should use condoms made from a material other than latex, such as polyurethane. Internal condoms are typically made from polyurethane and may be used multiple times. With proper use—and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthetic Rubber
A synthetic rubber is an artificial elastomer. They are polymers synthesized from petroleum byproducts. About of rubber is produced annually in the United States, and of that amount two thirds are synthetic. Synthetic rubber, just like natural rubber, has many uses in the automotive industry for tires, door and window profiles, seals such as O-rings and gaskets, hoses, belts, matting, and flooring. They offer a different range of physical and chemical properties which can improve the reliability of a given product or application. Synthetic rubbers are superior to natural rubbers in two major respects: thermal stability, and resistance to oils and related compounds. They are more resistant to oxidizing agents, such as oxygen and ozone which can reduce the life of products like tires. History The expanded use of bicycles, and particularly their pneumatic tires, starting in the 1890s, created increased demand for rubber. In 1909, a team headed by Fritz Hofmann, working at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoprene
Isoprene, or 2-methyl-1,3-butadiene, is a common volatile organic compound with the formula CH2=C(CH3)−CH=CH2. In its pure form it is a colorless volatile liquid. It is produced by many plants and animals (including humans) and its polymers are the main component of natural rubber. History and etymology Charles Greville Williams, C. G. Williams named the compound in 1860 after obtaining it from the pyrolysis of natural rubber. He correctly deduced the mass shares of carbon and hydrogen (but arrived at an incorrect formula C10H8 because the modern atomic weight of carbon was not adopted until the Karlsruhe Congress held later that year). He did not specify the reasons for the name, but it is hypothesized that it came from "propylene" with which isoprene shares some physical and chemical properties. The first one to observe recombination of isoprene into rubber-like substance was in 1879, and William A. Tilden identified its structure five years later. Natural occurrences Is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gutta-percha
Gutta-percha is a tree of the genus ''Palaquium'' in the family Sapotaceae, which is primarily used to create a high-quality latex of the same name. The material is rigid, naturally biologically Chemically inert, inert, resilient, electrically nonconductor, nonconductive, and thermoplastic, most commonly sourced from ''Palaquium gutta''; it is a polymer of isoprene which forms a rubber-like elastomer. The word "gutta-percha" comes from the plant's name in Malay language, Malay: translates as 'sticky gum' and () is the name of a less-sought-after gutta tree. The western term therefore is likely a derivative amalgamation of the original native names. Description ''Palaquium gutta'' trees are tall and up to in trunk diameter. The leaves are evergreen, alternate or spirally arranged, simple, entire, long, glossy green above, and often yellow or glaucous below. The flowers are produced in small clusters along the stems, each flower with a white corolla (flower), corolla with f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goodyear Tire And Rubber Company
The Goodyear Tire & Rubber Company is an American multinational tire manufacturer headquartered in Akron, Ohio. Goodyear manufactures tires for passenger vehicles, aviation, commercial trucks, military and police vehicles, motorcycles, recreational vehicles, race cars, and heavy off-road machinery. It also licenses the Goodyear brand to bicycle tire manufacturers, returning from a break in production between 1976 and 2015. As of 2017, Goodyear is one of the top five tire manufacturers along with Bridgestone (Japan), Michelin (France), Pirelli (Italian) and Continental AG, Continental (Germany). Founded in 1898 by Frank Seiberling, the company was named after American Charles Goodyear (1800–1860), inventor of Vulcanization, vulcanized rubber. The first Goodyear tires became popular because they were easily detachable and required little maintenance. Though Goodyear had been manufacturing airships and balloons since the early 1900s, the first Goodyear Blimp, Goodyear advertising ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleveland Clinic
Cleveland Clinic is an American Nonprofit organization, nonprofit Academic health science center, academic Medical centers in the United States, medical center based in Cleveland, Ohio. Owned and operated by the Cleveland Clinic Foundation, an Ohio nonprofit corporation, Cleveland Clinic was founded in 1921 by a group of faculty and alumni from the Case Western Reserve University School of Medicine. The Clinic runs a main campus in Cleveland, as well as 15 affiliated hospitals, 20 family health centers in Northeast Ohio, 5 affiliated hospitals in Florida, and cancer center in Nevada. International operations include the Cleveland Clinic Abu Dhabi hospital in the United Arab Emirates and Cleveland Clinic Canada, which has two executive health and sports medicine clinics in Toronto."Facts & Figures" Cleveland Clini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tires
A tire (North American English) or tyre (Commonwealth English) is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over which the wheel travels. Most tires, such as those for automobiles and bicycles, are pneumatically inflated structures, providing a flexible cushion that absorbs shock as the tire rolls over rough features on the surface. Tires provide a footprint, called a contact patch, designed to match the vehicle's weight and the bearing on the surface that it rolls over by exerting a pressure that will avoid deforming the surface. The materials of modern pneumatic tires are synthetic rubber, natural rubber, fabric, and wire, along with carbon black and other chemical compounds. They consist of a tread and a body. The tread provides traction while the body provides containment for a quantity of compressed air. Before rubber was developed, tires wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
