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Polymers are long chain giant organic molecules are assembled from many smaller molecules called monomers. Polymers consist of many repeating monomer units in long chains. A polymer is analogous to a necklace made from many small beads (monomers). Many monomers are alkenes or other molecules with double bonds which react by addition to their unsaturated double bonds.
The electrons in the double bond are used to bond two monomer molecules together. This is represented by the red arrows moving from one molecule to the space between two molecules where a new bond is to form. The formation of polyethylene from ethylene (ethene) may be illustrated in the graphic on the left as follows. In the complete polymer, all of the double bonds have been turned into single bonds. No atoms have been lost and you can see that the monomers have just been joined in the process of addition. A simple representation is -[A-A-A-A-A]-. Polyethylene is used in plastic bags, bottles, toys, and electrical insulation.
|Monomer||Polymer Name||Trade Name||Uses|
Non-stick coating for cooking utensils, chemically-resistant specialty plastic parts, Gore-Tex
|H2C=CCl2||polyvinylidene dichloride||Saran||Clinging food wrap|
|H2C=CH(CN)||polyacrylonitrile||Orlon, Acrilan, Creslan||Fibers for textiles, carpets, upholstery|
|H2C=CH(OCOCH3)||polyvinyl acetate||Elmer's glue - Silly Putty Demo|
|H2C=CH(OH)||polyvinyl alcohol||Ghostbusters Demo|
|H2C=C(CH3)COOCH3||polymethyl methacrylate||Plexiglass, Lucite||Stiff, clear, plastic sheets, blocks, tubing, and other shapes|
|Monomer||Polymer name||Trade name||Uses|
|H2C=CH-C(CH3)=CH2||polyisoprene||natural or some synthetic rubber||applications similar to natural rubber|
|H2C=CH-CH=CH2||polybutadiene||polybutadiene synthetic rubber||select synthetic rubber applications|
In this kind of polymerization, molecular rings are opened in the formation of a polymer. Here epsilon-caprolactam, a 6-carbon cyclic monomer, undergoes ring opening to form a Nylon 6 homopolymer, which is somewhat similar to but not the same as Nylon 6,6 alternating copolymer.
This material is based upon work supported by the National Science Foundation under Grant Number 1246120