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Introduction Natural rubber production The rubber tree Tapping and coagulation Development of the natural rubber industry Synthetic rubber production Polymerization methods The rise of synthetic rubber Additives The cure package Fillers Protective chemicals Plasticizers and processing aids Processing Mastication Mixing Shaping Curing.
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Natural rubber, also called India rubber or caoutchouc, as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of. Rubber is a material which can stretch and shrink. It is a polymer. It can be produced from natural sources (e.g. natural rubber) or can be synthesised on an .
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Desk Essentials. Polymerized chloroprene was developed by DuPont and given the trade name Neoprene.
In a number of cases, monomers which are not dienes are also used for certain types of synthetic rubber, often copolymerized with dienes. Some of the most commercially important addition polymers are the copolymers. These are polymers made by polymerizing a mixture of two or more monomers.
An example is styrene-butadiene rubber SBR - which is a copolymer of 1,3-butadiene and styrene which is mixed in a 3 to 1 ratio, respectively. SBR is more resistant to abrasion and oxidation than natural rubber and can also be vulcanized. A tiny amount is used for bubble-gum in the unvulcanized form.
Silicone rubber and other compounds, chemically called polysiloxanes , are not from conjugated dienes but have repeating units like -O-SiR 2 - where R is some organic radical group like methyl. The polymer rubber chains exist in random loose clumps in the unstretched state. At the nipple end of the balloon, there is lots of rubber and therefore many, many polymer chains - still loosely coiled.
These chains can be pierced without popping the balloon because the the chains can still be stretched.