Kevlar (poly-phenyleneterephtalamide)

The Chemical Formula of Kevlar is C14H10N2O2

Fig 1 - Kevlar molecule structure diagram

Kevlar’s scientific name is poly-phenylene terephthalamide, as it is formed by the synthesis of 1,4 – phenylene-diamene and terephthaloyl chloride which yields hydrochloric acid as byproduct. It is an organic compound. Because Kevlar has a structure that is made of many different atoms and molecules synthesized, it is unable to be found in nature; it is a manmade molecule. Its production is very costly as it is very difficult to arise it using concentrated sulphuric acid to keep the water-insoluble polymer inside the solution during spinning and the synthesis process. It is a poly - aramid, which is actually in the family of nylon fabric. Its heat resistance properties come from the aramid ring of Kevlar, and the high strength comes from the para structure.

Fig 2 - Stephanie Kwolek graduating from Margaret Morrison College

Kevlar was invented by a woman named Staphanie Kwolek while working for a company called DuPont. She mixed up chemicals that made other chemists think she was unusual and odd. She mixed a cloudy batch of polymers which at first seemed to not be going anywhere far, but her goal to create light, strong tires kept her going. Soon enough all of her experiments came to good use and a life saver, Kevlar, was born.

What was Kevlar first used for? It was in fact used first in road tires in lieu of steel ones. Not just in any road tires, but in the ones that need to be the most durable; racing tires. These days Kevlar is not just used for tires for cars, but many other things as well. It is used not surprisingly in body armour due to its high strength to weight ratio. If you took the same weight of steel and of Kevlar, Kevlar would be an unbelievably 5 times stronger. When woven, Kevlar is also used in underwater applications.

So what is the downside to using Kevlar? Kevlar does absorb moisture, and is more sensitive to the environment than rock or graphite. It is also hard to compress, and extremely difficult to cut, which you will need special scissors and a drill for curing laminates.

Fig 3 and 4 - The two main parts (1,4-phenylene-diamine and terephthaloyl chloride)

There are two parts to the composition of Kevlar. An amine (1,4-phenylene-diamine) and an acid chloride (terephthaloyl chloride). Phenylenediamine is an organic compound with a chemical formula of C6H4(NH2)2. It is a clear solid but normally has yellowish imperfections that are caused by imperfections. The uses of Phenylenediamine besides being used in Kevlar are a part of hair dye, a photography developing agent, and rubber antioxidants. Terephthaloyl chloride has a chemical formula of C8H4Cl2O2. It is a clear water white liquid. It is the flame resistant, chemical resistant, lightweight, and strong part that makes up the Kevlar. It has few other uses but it is used to make Twaron. 

Fig 5 - A Kevlar bulletproof vest

Kevlar is the best molecule in the world because it saves your life. What is better than something that keeps you living? There is nothing better than staying alive. Kevlar is bound together to make incredibly strong light weight material. That is why it is the best. .

Sources Used:

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"Kevlar - Molecule of the Month 2010 - HTML-only version."School of Chemistry - Bristol University - UK. N.p., n.d. Web. 21 May 2011. <http://www.chm.bris.ac.uk/motm/kevlar/kevlarh.htm>.

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Zumdahl, Steven S., and Susan A. Zumdahl. Chemistry . 6. ed. Boston, Mass.: Houghton Mifflin, 2003. Print.