Section B12
PAPER#2188
THE USE OF POLY-PARAPHENYLENE TEREPHTHALAMIDE (KEVLAR) IN
PERSONAL BODY ARMOR
Daniel Chilutti (dsc31@pitt.edu), Erik Schaub (ehs9@pitt.edu)
Abstract— War is a very relevant and emotional
inevitability in our society. To prevent injury and loss of life,
armor has been used in combat for many centuries. Over
time, weapons gained strength, and armor was no match for
these weapons. Scientists have longed to develop a material
that is practical and effective in the protection from
firearms. The solution to this problem was discovered by
DuPont in 1965 while trying to make stronger steel belting
for vehicle tires [1]. One mixture of an aromatic polyamide
had odd qualities that were inconsistent with others. The
polyamide was spun and became what we now know of as
Kevlar. Kevlar has a unique molecular structure that allows
it to be strong yet flexible. This dense and compact structure
is what makes Kevlar five times stronger than steel by
weight. One concern about Kevlar is its byproduct. Kevlar
uses a unique process involving sulfuric acid, which is a
very toxic acid. There is much work being done to prevent
any harm from this process and its byproducts.
DUPONT AND THE UNLIKELY CHEMICAL
Before 1965, the field of polymer science was very small.
One major polymer that had been invented before this 1965
was Nylon. Nylon has its origins at the chemical company
DuPont. DuPont is a large chemical company that has
worked to produce innovative products since it was founded
in 1802 [2].
In 1965, DuPont had been trying to find a new fiber
that was strong and flexible so that it could be used in racing
tires. Before, steel was the main component to hold the tires
together. Steel had a few problems, one being its high
weight. What DuPont planned to accomplish for tires was to
find a replacement for steel that made the tires lighter and
stronger. This would make tires that are lighter while being
able to last longer. As a byproduct this would also improve
fuel economy for commercial vehicles and reduce the
dependence on oil, an objective of DuPont. Stephanie
Kwolek, a chemist at DuPont, was assigned to this project
[3].
Not much was known about synthetic fibers at the
time, but Kwolek was an up and coming pioneer in the field.
With the knowledge of the time and her own chemical
intuition, she started making mixtures of different aromatic
monomers. One mixture presented unexpected behavior. It
was very fluid, turbid and buttermilk-like in appearance. The
man in charge of the spinnerets refused to spin the mixture
that Kwolek created because he thought the turbidity of the
solution would damage the spinning machine. Kwolek
insisted that the machine would be able to handle the
sample, and that he should spin it [3]. The result was
incredible and much more than Kwolek or any of the other
chemists had hoped for. The fibers were stronger than any
they had ever seen before and it was due to its specific
creation process.
In this paper we will discuss the chemical structure of
Kevlar and how its structure causes its unique mechanical
properties. Kevlar has massively improved the field of
personal body armor, resulting in fewer casualties due to
gunshot wounds. We will discuss the environmental effects of
the production of Kevlar as well as the ethics of the use and
production of Kevlar because of its beneficial effects at the
battlefront.
Key Words— Kevlar, Materials Science, Polymers, Body
Armor, Organic Materials, Molecular Structure.
KEVLAR: A MODERN MARVEL
Can you imagine a flexible material that is lightweight,
stronger than steel, and resistant to fire? This material exists
and it is called Kevlar. Kevlar was created in 1965 at a
DuPont lab. It was originally supposed to be used in tires to
make them lighter. The tires would be lighter because of
Kevlar’s physical properties which arise from a specific
production process. The uses for Kevlar are numerous. We
will show the importance of Kevlar by touching on all of the
uses it has to offer, mainly its use as body armor. Body
armor in some cases is a mixture of ceramic plates enclosed
in a very strong flexible material, in this case Kevlar. In
other cases they wrap the Kevlar in a plastic liner. The
strength of Kevlar originates from its molecular structure.
Another component which leads the structure is the
particular way it is formed. However, there are some ethical
concerns with Kevlar such as chemical byproducts, UV
degradation, and its use in war. To understand Kevlar, it is
important to first know of its origins.
THE PROCESS OF CREATING KEVLAR
Kevlar is produced by the chemical reaction of terephthaloyl
chloride with para-phenylenediamine [4]. The two
monomers undergo a condensation reaction that is carried
out multiple times. It is a condensation reaction because for
each individual reaction there is one unit of hydrochloric
acid produced [4]. This type of reaction is known as a
polymerization. A polymerization reaction is a process
where monomer molecules, in this case terephthaloyl
chloride and para-phenylenediamine, combine together to
make another molecule. This reaction will happen many
times and results in long chains of molecules known as
polymers.
University of Pittsburgh
Swanson School of Engineering
April 14, 2012
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Daniel Chilutti
Erik Schaub
composites for marine sporting goods and aerospace
applications. The other grades of Kevlar are 100, 119, 129,
AP, and XP. These other grades have applications in areas
such as protective apparel, rubber goods, ballistic materials,
and ropes and cables [7].
Over the past decade DuPont has been expanding its Kevlar
production. DuPont invested $50 million to increase its
production capacity of Kevlar at their plant in Richmond
Virginia [8]. In October, DuPont announced the opening of
its $500 million Cooper River Kevlar Facility. With this
plant their overall global production will be increased
initially by 25% and will grow to 40% over the next two
years according to DuPont [9]. In 2005 a new research and
development facility was opened in China. This facility is
one of the more than 75 research and development facilities
operated by DuPont [11]. DuPont has been expanding their
Kevlar production because the demand for Kevlar has grown
greatly due to its unique properties.
FIGURE 1
THIS IS THE STRUCTURE OF THE KEVLAR FIBERS [2].
The reaction occurs under anhydrous conditions at
temperatures between -15o C and 30o C [4]. During the
reaction hydrochloric acid is produced as a product of the
two monomer molecules. This acid is may cause significant
corrosion problems in processing equipment such as the
spinneret. Therefore it is necessary to add a base to the
solution to neutralize the acid [4]. The preferred bases are
lithium and calcium salts. The solution of the two monomers
is stirred continuously for two to twenty four hours as the
polymer forms [4].
After the stirring is complete, the solution has
turned into a viscous, gel-like mass. In addition to the
desired compounds there may be some insoluble salts
formed [4]. It is necessary to remove these salts before the
material is pressed or spun. After these impurities are
removed the fiber may be concentrated under vacuum to
produce the fluid desired for spinning. To isolate the poly(pbenzamide) the mixture is combined with water in a suitable
blender and then is converted to a powder. This powder is
washed with water and alcohol and is dried overnight in a
vacuum oven at about 60o-70 o C [4]. The Kevlar fibers are
all that is left and they are ready to be spun.
Kevlar yarn is spun in a process known as wet
spinning. In this process, a solution of 100% anhydrous
sulfuric acid and Kevlar fibers are pushed, under pressure,
through small holes [4]. The device that the dissolved
polymer is passed through is called a spinneret. As the
molecules pass through the tiny holes in the spinneret they
are all aligned in a uniform position [5]. As they leave the
spinneret, the newly formed yarn is cooled and solidified by
cold water. Then the fiber is heated slightly, hardening it,
and is spun up on a spool [6]. This is the final product of the
Kevlar production process and now the yarn is ready to be
sold.
Kevlar comes in different grades. These grades
have different properties and therefore are used for different
purposes. DuPont, the manufacturer of Kevlar, makes seven
different grades [7]. Kevlar 29, which was the original make
of Kevlar, is used in ballistic applications, ropes and cables,
protective apparel such as cut resistant gloves, and as rubber
reinforcement in tires and automotive hoses [7]. Kevlar 49 is
used in fiber optic cables, plastic reinforcement, and in
PRODUCTION COSTS OF KEVLAR
One thing about Kevlar that deterred its inception was the
high production cost. Originally, DuPont feared that Kevlar
might cost more than they could reasonably sell it for.
First of all, not just anyone can produce Kevlar.
The proper equipment is required to carry out just the right
reaction to create it. DuPont was able to produce Kevlar
because it was an already established chemical company
with both research and production facilities. Not many other
companies, at the time, had the same resources that DuPont
had.
Secondly, the reaction process calls for
concentrated sulfuric acid to keep the polymers dissolved in
the solution. Sulfuric acid is not only dangerous, but very
expensive. Due to it being dangerous, it is expensive to
handle and contain. Along with this, it is a painstaking
process to get the sulfuric acid so concentrated, so there is
another contributing factor to its high cost [12].
In addition to all these prior costs, there is also the
cost of labor. Workers at DuPont were certainly not
underpaid, which means that a lot of their profit goes to the
hard working employees. While it may seem unlikely for
Kevlar to be profitable, the applications for it are so
incredible that consumers were willing to pay the high
prices.
THE INCREDIBLE PROPERTIES OF KEVLAR: A
MOLECULAR STRUCTURE ANALYSIS
Kevlar is known for its strength. This strength comes from
certain properties of the long chain molecule. One property
of Kevlar that makes it strong is its alignment with respect to
the other Kevlar molecules. The long chain molecules are
aligned parallel to each other. This molecular alignment is
unique to Kevlar because of the rigidity of the molecule
itself [10]. This rigidity arises from the para orientation of
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427o C and 482o C in air depending on the grade used [5].
The family of aramid fibers, to which Kevlar belongs, has
fire resistant properties; meta-aramid fibers are marketed as
heat resistant materials. Para-aramid fibers, which include
Kevlar, have more market applications but are still flame
retardant [13]. Kevlar can operate in temperatures up to
190o C without any adverse effects on its strength. Though
Kevlar is flame resistant, it can still be ignited. Kevlar has a
limiting oxygen index of 29; limiting oxygen index is the
minimum concentration of oxygen, expressed as a
percentage, necessary to support combustion of a polymer
[13]. During ignition, Kevlar fibers do not melt but glow.
After the material is removed from the flame no after
burning is observed [5]. Because of this Kevlar is classified
as a self-extinguishing material. While being burned Kevlar
does not drip. This is a common occurrence with organic
fibers and may lead to flame propagation. At temperatures
above 450o C the surface of Kevlar fibers will char. This
charring will protect the other fibers from the flame [13].
Burning Kevlar will produce combustion gasses. These
gasses are mostly carbon dioxide, water, and oxides of
nitrogen. However, carbon monoxide small amounts of
hydrogen cyanide, and other toxic gasses may be produced
depending on the burning conditions [5].
In addition to its fire resistance, Kevlar exhibits
other interesting properties when it is exposed to heat.
Furthermore, when it is exposed to elevated temperatures,
Kevlar, unlike other organic fibers, does not experience any
shrinkage [5]. Other fibers such as nylon suffer significant,
irreversible shrinkage. Another striking property of Kevlar is
that its specific heat varies with temperature. As the
temperature of the Kevlar fibers increases, the specific heat
of the fiber increases as well. The increase in specific heat is
significant, it more than doubles when the temperature is
raised from 0o C to 200o C [5].
Furthermore, in arctic conditions (-46o C) the
tensile properties of Kevlar are not adversely effected. In
fact, Kevlar actually gets slightly stronger at low
temperatures. These effects can be attributed to a slight
increase in molecular rigidity. In cryogenic temperatures (196o C) Kevlar shows no embrittlement or degradation [5].
Like many other polymers, Kevlar is sensitive to
UV light. Unprotected fibers tend to be discolored from
yellow to brown after prolonged exposure [14]. Extended
exposure can lead to loss of mechanical properties
depending on wavelength, exposure time, radiation intensity,
and the shape of the Kevlar product [5]. Degradation only
occurs in the presence of oxygen and is not enhanced by any
other factors such as moisture or atmospheric contaminants.
Two specific requirements must be met before light of a
particular wavelength causes degradation: first, the polymer
must absorb the light; and second, the light must have
sufficient energy to break the chemical bonds [5]. The
required wavelength that is found in nature that can degrade
the Kevlar fibers occurs between the wavelengths of 300 nm
and 450 nm [13]. The Kevlar must be protected if it is being
the benzene ring that is the backbone of the molecule. With
rigid polymers, as the concentration increases the molecules
begin to align parallel to each other. As the solution
containing the Kevlar molecules is spun, the molecules that
are randomly aligned emerge with an almost uniform
molecular orientation. As the Kevlar fibers are spun this
orientation remains intact and contributes to the strength of
the fibers [5].
Another property of Kevlar that leads to its high
strength is the intermolecular hydrogen bonding present
between neighboring molecules [10]. The hydrogen bonding
occurs between partially positively charged Hydrogen atoms
and the partially negatively charged carbonyl group.
Because these two groups are present in the amide bond
between each individual monomer this hydrogen bonding
occurs consistently between the multiple long-chain
molecules.
The chemical makeup of Kevlar makes it
amazingly strong. The tenacity of the fiber is the breaking
strength of the fiber divided by the denier. The denier is the
mass if the fiber per 9000 meters. The tenacity of Kevlar is
measured to be 424000 psi. In comparison the tenacity of
steel wire is measured 285000 psi and the tenacity of
fiberglass is measured to be 66500 psi. The density of
Kevlar in lb/in3 is measured to be 0.052 while the densities
of steel wire and fiberglass are 0.280 and 0.090 respectively
[5]. With these values, we can calculate the specific tensile
strength of these materials. By dividing the tenacity by the
density we obtain the ration of weight to strength. The
specific tensile strengths of Kevlar, steel wire, and fiberglass
are 8.15, 1.0, and 7.40 respectively. By this comparison we
can see that by weight Kevlar is more than 8 times stronger
when being under tension along the length of the fiber [5].
Kevlar is chemically stable under a wide variety of
exposure conditions. However, when the fiber is treated with
aqueous strong acids, strong bases, or sodium hypochlorite,
degradation can happen [5]. The effect of degradation on the
Kevlar fiber weakens it and reduces its breaking strength.
This degradation occurs particularly over long periods of
time and at elevated temperatures. Certain acid or base
solvents cause more degradation than others while some
solvents cause no degradation at all. Furthermore, the
amount of degradation observed in the fiber may vary
drastically with different concentrations of the solvent,
temperature of the solution, and time of exposure to the
selected solvent. For example when treated with a 40%
(w/w) solution of sodium hydroxide at 21 o C for 100 hours
there was no strength loss in the fiber. However, with a 10%
solution of sodium hydroxide at 99o C for 100 hours there
was total degradation of the fiber [5]. Even though the
structural integrity of the Kevlar fibers decay as the pH
deviates from 7 in either direction, acidic conditions cause
more severe degradation than basic conditions that are
equidistant from neutral [5].
One unique property of Kevlar is that it does not
melt. It decomposes at relatively high temperatures between
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Erik Schaub
used in areas in which it could be exposed to light of that
wavelength. Only small amounts of this light occur in
artificial light sources such as incandescent or fluorescent
light bulbs or in sunlight filtered by glass. Kevlar is selfscreening; therefore external fibers form a protective barrier
which shields inner fibers from the harmful UV light [14].
The stability increases with size, so thicker materials will
have more protection. It is possible to avoid this problem
with light by covering the Kevlar with other fibers or by
putting a jacket over the exposed area.
each other and help to reinforce the area that was impacted.
The plastic liner also helps to absorb some of the energy of
the bullet [15]. The Kevlar fiber which composes the vest is
able to handle these impacts without failing because of the
high tenacity of the fibers as was described in the properties
section. As the bullet impacts the vest the fibers stretch and
are able to absorb the energy of the impact without being
destroyed. There are many different styles of ballistic body
armor but the use of Kevlar or Kevlar-like fibers are
common in all of them.
One specific example of body armor that utilizes
Kevlar is the Interceptor body armor. The Interceptor body
armor is commonly used by United States combat troops
overseas and it is standard issue. This set of body armor uses
Kevlar along with other ceramic plating to provide
protection for the wearer [17].
Another use of Kevlar is in sporting goods. Because
of Kevlar’s strength it is used to reinforce and lighten
products. Some applications involve the hulls of boats such
as canoes, kayaks, and sailboats. Because they are made of
Kevlar these boats are much lighter and are much more
resistant to damage when compared to boats with hull made
of other materials [18]. Kevlar is also used in sporting goods
including tennis rackets, snowboards, and helmets [19].
Kevlar is also used in tires. Kevlar was originally
synthesized when DuPont was looking to make a substitute
for steel in racing tires. Today Kevlar is still used in tires to
help maintain strength and to resist being punctured by
objects that the tire may run over. Kevlar is used to help
reinforce the sidewalls of tires which contribute to greater
stiffness in the tires. This aids in cornering and overall better
maneuverability in the tires [9]. Another application of
Kevlar in tires is to help reduce the noise produced while
driving. Kevlar reinforced rubber has been adopted and
marketed by tire companies such as Goodyear [9]. In the
future Kevlar could be used to replace steel in the bead area
of the tire. The bead is the edge of the tire that sits on the
wheel. If you were to replace all of the steel beads on a
Boeing 747 jet with Kevlar composite materials you could
reduce the overall weight by 1,700 pounds. This would lead
to better fuel economy in the jet [9].
THE REASON WE KNOW THE NAME ‘KEVLAR’
Kevlar’s unique chemical structure allows it to have multiple
uses. The use it is most known for is its role in ballistic
materials such as body armor, but it has many uses ranging
from sports equipment to ropes to tires. Most of these
applications rely on Kevlar’s strength.
The most famous application of Kevlar is its use in
ballistic materials such as body armor. Kevlar is used in
body armor because of its high strength to weight ratio.
Kevlar’s role in ballistic armor is to stop the projectile and
absorb the energy of the impact. Inside the vest there are
multiple layers of Kevlar and plastic film. Together these
layers make the vest effective in stopping bullets [15]. A
bullet has a large amount of kinetic energy after being fired
and will cause damage to the person on the receiving end.
To stop the bullet, the Kevlar fabric is woven tightly
together in an interlaced pattern. If looked at under a
microscope the pattern looks like small squares uniformly
distributed over the surface [15].
THE FUTURE OF KEVLAR
Even though Kevlar has been used in hundreds of different
products since it was discovered, there are still people out
there developing new and innovative uses for it. Contrary to
popular belief, Kevlar is not just used in the military and in
law enforcement but it had many commercial uses as well.
One up and coming use for Kevlar is in cookware.
Because of Kevlar’s miraculous ability to withstand high
temperatures, it is often used as a lining underneath a Teflon
coating on the surface of pots and pans. Kevlar provides
safety and convenience when used in this way. Along with
lining in pots and pans, Kevlar has been integrated into
cooking gloves. These gloves provide consumers with
FIGURE 2
THIS IS A VISUAL REPRESENTATION OF THE STRUCTURE OF A KEVLAR VEST
[15]
This dense weave is what is responsible for
stopping the bullet. The Kevlar weave absorbs the impact of
the bullet and spreads the energy of the bullet out along the
fabric in the vest. Because of the way the Kevlar fiber is
woven it can spread out the energy of the bullet impact in all
directions. Furthermore, the interwoven Kevlar fabric can
take the impact from a bullet in any direction. As the bullet
makes contact with the vest the interlocked fibers all pull on
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Erik Schaub
protection against temperatures of up to 540 degrees
Fahrenheit [20]. To add to these gloves capability, the
strength of Kevlar also protects against accidental knife
injuries while cutting food. If more people used these gloves,
knife injuries in the kitchen would drastically decrease.
Fiber optics is a new technology that has gaining
recognition in the technological community. Kevlar provides
strength and protection against mechanical stresses [20].
Proper conduction is very important to signal transduction in
fiber optic cables and if any object were to crush or cut the
cable the signal would be interrupted. Kevlar’s strength acts
to protect the cables from being crushed and adding to the
reliability of the connection.
One under looked problem in households is the
flammability of mattresses. Modern mattresses contain very
flammable materials. A common attempt to counter this is to
include fire resistant materials inside the mattress to prevent
a fire from reaching it. However, this is not the most
effective way of solving the problem. Recently, mattresses
have been made with Kevlar weaved into the outer lining.
This decreases the chance of a fire entering a mattress and
igniting the flammable materials inside [20]. Certainly this is
a very beneficial thing for all mattresses to have.
With all these new technological uses for Kevlar, it
is easy to think that it will eventually run out of new uses.
However, the research in this world is always expanding and
there is bound to be new applications of this material that
will benefit all.
chemical in a very useful way. They must control it and
dispose of it properly as to not harm anyone. To do this the
acid was converted into the useful compound called gypsum.
This compound can be used by wallboard and cement
manufacturers [12]. The environment is a large concern
when dealing with sulfuric acid. The companies do a good
job with handling the chemicals in the production properties.
With this control of harm, the use of sulfuric acid can be
justified and seen as ethical.
Another concern is whether manufacturing of a
product used to aid in warfare is ethical. Even though Kevlar
is used to protect people from harm, people are likely to
associate anything related to war to be ethically
questionable. It is very important to distinguish between the
two main types of items produced for war: those that aid in
the destruction of people and property, and those that protect
people and their property. Kevlar is strictly one of the
products that aids in the protection of lives by protecting
soldiers and law enforcement officers from enemy fire.
There are many stories of soldiers who had their lives saved
by a Kevlar vest. One account that supports this claim comes
from USA Today about a U.S. Army veteran. “In a daylong
firefight last year against the Taliban in a snow-covered
Afghan valley, Army soldier Jason Ashline was struck by
two bullets from an AK-47 assault rifle. The slugs lodged
harmlessly in his flak jacket.” Ashline went on to say, “The
bullets knocked me over and took the wind out of me, but I
didn't feel any pain”[21]. This story provides real life
evidence of how the vest is ethical because of its ability to
save lives.
Deceit and trickery are unethical acts. As discussed
earlier, a major problem with Kevlar is how it degrades
when exposed to UV lighting. Because it could mean life or
death, users of Kevlar should know the dangers they face if
the Kevlar material degrades. This is where the producers
have been good at providing relevant information to their
customers. It is the production company’s ethical duty to
prevent this from happening to their material. One way
companies have approached solving this goal is by covering
Kevlar in extra material that is resistant to UV lighting
degradation and also protects the under layer of Kevlar from
the light. It is important to note that the companies still
choose to warn consumers of this effect even though they
have worked to make the problem almost nonexistent. They
explain the process and its ability to lower the strength of
Kevlar. The fact that the companies are going out of their
way to prevent product failure, warn consumers of the
slightest chance of failure, and make advances to end
chances of failure is what makes the production of Kevlar
products ethical.
Although there are many aspects to Kevlar that
seem to hinder the progress of the product such as a strong
acid byproduct, a strong acid used in production, Kevlar’s
use in war, and UV degradation of the fibers. These aspects
are being openly countered and controlled by the producers.
The acids are being contained and disposed of properly to
ETHICAL CONCERNS OF KEVLAR
There are some cases in which the ethics of the production
and uses of Kevlar can be questionable.
The first questionable ethical concern of Kevlar is
that the production process yields concentrated HCl
(hydrochloric acid). HCl is one of the seven strong acids.
One of the properties of a strong acid is the ability to break
down and degrade substances, altering them chemically.
This means that the acid has the capability to harm anything
it touches. It can also lead to severe bodily harm if a
worker’s skin or eyes were to come into contact with it. That
is why these producers work to contain and control the acid.
By neutralizing the acid, it becomes weaker and is able to be
handled and disposed of properly. Along with its
controllability, this acid is used as a reactant in many
industrial processes. This means that it can easily be reused
and turns from a harmful byproduct into a useful product.
With this alternative use for the harmful byproduct, it is
obvious that this factor is no longer an unethical one.
Along with the byproduct of HCl, another
dangerous chemical is involved in the production process of
Kevlar. In the spinning process the strong acid H2 SO4 , or
sulfuric acid, is used to keep the water insoluble fibers
dissolved in the solution. This acid is expensive to purchase,
and it is also dangerous to handle and dispose of. It is very
important for the producers of Kevlar to deal with this
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Erik Schaub
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html
[19] “Applications of Kevlar”. [Online Article]. Availible:
http://www.odec.ca/projects/2004/clar4c0/public_html/en/applications.html
[20] “Other Uses for Kevlar.” [Online Article]. Available:
http://www2.dupont.com/Kevlar/en_US/uses_apps/other_uses.html
[21] J. Swartz, E. Iwata. (2003, April). USA Today [Online]. Available:
http://www.usatoday.com/money/world/iraq/2003-04-15-kevlar_x.htm
reduce the chance of bodily harm. Kevlar is being used as a
form of protection rather than something to harm people in
warfare. Also, the producers of Kevlar are telling their
clients of minor flaws of the material, and they have devised
ways to protect against this process, all so that the failure of
the product and ultimately the loss of life will be prevented.
KEVLAR IS AND WILL CONTINUE TO BE A MAIN
COMPONENT OF MATERIALS OF THE FUTURE
Unfortunately, the world is not free from the atrocity that is
war. It is for this reason that people work toward creating
ways to protect those involved in war from this inevitability.
One way this protection is being reached is through the use
of Kevlar as armor. Kevlar has a rich background which has
its roots in DuPont. Its conception happened when DuPont
researched ways to make tires stronger while reducing the
weight of them. The polymer was created by accident and
was found to have incredible properties such as having high
tensile strength, being lightweight, and being resistant to
fire. These properties result from the unique chemical
structure of Kevlar. The production process aligns the
molecules in the fiber in such a way that they are bonded to
each other with an intense strength. Through much research
and development, this material was refined into what is now
known as Kevlar. Many uses have been discovered for this
product such as body armor, sporting goods and automobile
tires. Kevlar may seem to have many negative factors but
these have been minimized thus giving Kevlar a positive
ethical standing. Kevlar is continually being used in new
ways to create new and useful technology. What will be
thought of next?
ACKNOWLEDGEMENTS
We would like to thank the department of Materials Science
and Engineering for guiding us towards the field of
Materials Science and Engineering. If not for this, we would
have not chosen to learn more about Kevlar, which is a very
interesting material to learn about. We would also like to
thank the department of Freshman Engineering for giving us
an opportunity to write papers for a conference, as this will
be an integral part of our future as Engineers. We would like
to thank our co-chair, Julia Ramone, and our chair Robert
Boback.
ADDITIONAL SOURCES
A. Clements , M. Dunn , V. Firth , E. Hubbard , J. Lazonby and D.
Waddington. (2010, Nov.). “Kevlar and Composites.” Chemistry Review.
pp. 24.
M. G. Dobb, D. J. Johnson, B. P. Saville. (2003, March). “SupraMolecular
structure of a high-modulus polyaromatic fiber (Kevlar 49).” Wiley Online
Library.
[Online]
Available:
http://onlinelibrary.wiley.com/doi/10.1002/pol.1977.180151212/abstract
McGouldrick, Kevin, Owen B. Toon, and David H. Grinspoon. "Sulfuric
acid aerosols in the atmospheres of the terrestrial planets." Planetary and
Space
Science. 59.10
(2011): 934-931. [Print].
Available:
<http://www.sciencedirect.com/science/article/pii/S0032063310001583> .
REFERENCES
[1] V. Lambert. (2009, April) “Enhancement of spike and stab resistance of
flexible armor using nanoparticles and a cross-linking fixative.” Florida
Atlantic University. pp. 11
[2] (2012) “DuPont.com: Company at a Glance.” DuPont. Available:
http://www2.dupont.com/Our_Company/en_US/glance/index.html
[3] (2010, Nov.). “Kwolek: The Creator of Kevlar.” Chemistry review. pp.
19.
[4] S. Kwoleck. (1971, Sep 7). “United States Patent 3,819,587”. [Online
Patent].
Available:
http://www.google.com/patents/US3819587?printsec=description#v=onepa
ge&q&f=false
J. Swartz, E. Iwata. (2003, April). USA Today [Online]. Available:
http://www.usatoday.com/money/world/iraq/2003-04-15-kevlar_x.htm
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Daniel Chilutti
Erik Schaub
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