Thursday, November 14, 2019
Polymers :: essays research papers
 Polymers are large molecules  composed of smaller molecules called monomers.  Monomers are produced and either grow together  or are assembled to produce a single polymer.  There are synthetic and natural polymers. Some  examples of natural polymers would be wood,  starches, fingernails, and hair. Synthetic polymers  are usually referred to as plastics. Petroleum, is the  primary monomer used to produce polymers. An  English chemist named Alexander Parkes was the  first scientist to produce the first synthetic polymer  in 1862. John Wesley Hyatt, an American, was  the first person to produce a useable polymer two  years later. He named the product celluloid. The  prime virtue of polymers is a high  strength-to-weight ratio. Industrial-strength  polymers surpass titanium in tensile strength. To  add strength and improve flexibility, polymers are  sometimes fortified with short-fiber additives,  mostly fiberglass. This is known as a polymer  composite. One particular polymer has three times  the strength of tempered steel and is being used in  bullet proof vests. Another composite will be used  to fasten together the sections proposed space  stations. Polymers have also been used in cars,  including the Chevrolet Camaro and the Pontiac  Fiero. New polymers are being created with more  strength and flexibility by combing two chemically  different polymers and producing a block  copolymer. Combinations of block copolymers  and composites and intended for use in booster  rockets and in materials of Earth-orbiting  installations. Most common polymers are usually  solid, but a new class of polymers is being  introduced in a liquid crystal state. Although these  polymers still have the physical characteristics of  liquid, they are structured more like solids. Many  liquid crystals are transparent at one temperature  and colored at another temperature. This makes  them suitable for use in liquid crystal displays, such  as in digital watches, hand-held calculators, and  lap-top computers. A new liquid polymer,  consisting of a mixture of iron and nickel, is being  used to make metal links that can be used in  paper, glass, and on electronic circuit boards.  Despite the development and widespread use of    					    
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