Macromolecules
Kevlar
An Introduction:
Kevlar is a para-aramid synthetic fibre that is used for a variety of purposes that include but is not limited to: clothing, accessories, equipment, cables, bulletproof vests, windsurfing sails and armour. It was invented by Stephanie Kwolek in 1971 in anticipation of a gasoline shortage. This manmade organic fibre is lightweight yet extremely strong with approximately five times the strength of steel on an equal-weight basis. Besides that, Kevlar also has a high chemical resistance, high cut resistance and is flame resistant.
The Structure:
Kevlar is formed by the reaction of 1,4-phenylene-diamine (para-phenylenediamine) with terephthaloyl chloride. The other product of this condensation reaction is hydrochloric acid [HCl], though it is considered a by-product. The chemical reaction can be represented as follows:
The Linkage:
The structural formula of Kevlar is [-CO-C6H4-CO-NH-C6H4-NH-]n. The molecular structure of Kevlar can be represented as follows:
References
Bellis, Mary. "The History of Kevlar - Stephanie Kwolek." About.com Inventors. The New York Times Company. Web. 19 May 2012. .
"Better, Stronger and Safer with Kevlar Fiber." DuPont. E. I. Du Pont De Nemours and Company. Web. 19 May 2012. .
Hallick, Richard, and Madeleine Lapointe. "Large Molecules Problem Set." The Biology Project [Online]. The University of Arizona. Web. 19 May 2012. .
Helmenstine, Anne Marie. "What Are Some Examples of Polymers?" About.com Chemistry. The New York Times Company. Web. 19 May 2012. .
"LBNL - KEVLAR." Lawrence Berkeley National Laboratory. University of California. Web. 19 May 2012. .
"Macromolecular Chemistry." Citizendium.org. Web. 19 May 2012. .
"Macromolecules." Reading List. California Department of Education. Web. 19 May 2012. .
"Tutorial 3.2 Macromolecules." W.H. Freeman Publishers. Macmillan. Web. 19 May 2012. .
"USES AND APPLICATIONS: DuPont Kevlar." DuPont. E. I. Du Pont...