STRUCTURE
Kevlar Aramid Fiber is a synthetic (man-made) material known as a Polymer. A polymer is a chain that is made up of many similar molecular groups, better known as ‘monomers’ that are bonded together. ‘Monomers’ are made up of fourteen Carbon atoms, two Nitrogen atoms, two Oxygen atoms and ten Hydrogen atoms. A single Kevlar polymer chain could possibly have anywhere from one to five million monomers bonded together.
A group of polymer chains can be organised together in a fiber. How the polymer chains are put together is important, as it improves the properties of the material. The flexibility, strength and stiffness of Kevlar fiber, is dependent on the orientation of the polymer chains. Kevlar fiber is an arrangement of molecules, orientated parallel to each other. This orderly, untangled arrangement of molecules is described as a “Crystalline Structure”. A manufacturing process known as ‘Spinning’ is needed to achieve this Crystallinity structure. Spinning is a process that involves forcing the liquefied polymer solution through a ‘die’ (small holes).
The Crystallinity of Kevlar Polymer strands, contributes to the unique strength and stiffness of the material. Kevlar is very similar to other common synthetic polymers, including Nylon, Teflon and Lycra. In all Polated to strength. Aromatic refers to the Carbon atoms attached in a ring, and Amides refers to a group of Carbon, Nitrogen and Hydrogen atoms. Kevlar fiber is therefore a “Polyaromatic amide”, as it has a high breaking strength.
Polymer chains are long, individual chains, although they behave as if they are attached to each other. The individual chains are actually held together by ‘Electrostatic Forces’ between molecules, also known as ‘Hydrogen Bonds’. Scientists discovered this, by using a special type of X-ray microscopy called ‘XANES’. This was able to reveal the orientation of molecules in materials. It has also been discovered that the components of Kevlar fiber, have a radial orientation that is in a crystal. The crystal-like regularity is the largest contributing factor in the strength of Kevlar fiber.
PROPERTIES
It is five times stronger, yet the same weight as steel. Kevlar Aramid fiber is an improved material, which is an extremely lightweight, man-made organic fiber. Kevlar fiber has a combination of properties, which have made Kevlar a very useful material. These include, high strength, low weight, high chemical resistance and high cut resistance. This material does not corrode or rust and is also unaffected when placed in or under water.
spaced –CONH– amide groups. Nylon 6-6, or poly(hexamethylneadipamide), is composed of. two structural monomers (hexamethylendiamine (H2N(CH2)6NH2) and adipic acid. (HOOC(CH2)4COOH), whereas Nylon 6, or poly(6-caprolactam), is composed of a single structural unit (either 6-aminocaproic acid (H2N(CH2)4COOH) or caprolactam). Ultimately, the answer is yes.
Kevlar (10) - synthetic fiber that is often used as a reinforcing agent in tire and other rubber products. I is made up of high tensile strength.
The characters in “Everyday Use” by Alice Walker serve as a comparison between how family heritage and traditions are viewed. Walker illustrates that heritage is represented not by the possession of items or how they look, but buy how they are used, how one’s attitude is, and how they go about a daily lifestyle. Every memory or tradition in “Everyday Use” strengthens the separation in the relationship between Dee and her mother, the narrator, which involves different views on their family heritage.
She doesn’t envy her sister Dee’s new style of life, even though she lacks a higher level of education. The opposite, she enjoys her lifestyle, “Maggie still lives in poverty with her mother, putting “priceless” objects to “everyday use” (‘everyday use”). Despite the fact she always felt inferior to her older sister Dee, Maggie expresses her respect for family’s heritage collaborating with Mama, cleaning the house for Dee’ visit, “I will wait for her in the yard that Maggie and I made so clean and wavy yesterday afternoon” (Walker 23). Maggie gives the quilts to Dee because she wanted it even though she was preserving them for her wedding day. It represented for her an invaluable symbol of her heritage, “The quilts contains pieces of family history, scraps from old dresses and shirts that family members have worn” (“everyday
Sources believe social media is a large aspect to why Americans are drastically polarized today. In an article by Nicholas Carr called “How Social Media Is Ruining Politics” Carr states “The
This maximises the intermolecular forces between the chains as they are able to pack closely together. However, this reduces the flexibility and is therefore quite rigid and strong. This isotactic polyvinyl chloride structure occurs very little. Another structure that is produced very little is the syndiotactic PVC. The syndiotactic PVC has a regular arrangement and has similar properties of flexibility, rigidity and strength to the isotactic PVC as shown in Figure #.
...r is a strong and flexible material. When Kevlar is combined with resin it is 20 times stronger than steel. Kevlar is light weight and has a good material to weight ratio. Kevlar is inflammable and therefore can be used as an outer layer in suits. The physical property of the fabric allows it to sustain high temperatures and can tolerate extreme environmental conditions. Kevlar has a very high impact structure, is a water and scratch resistant fibre. Kevlar when combined with other materials forms textiles products which is fire and water resistant. Draw backs of Kevlar is that it absorbs moisture. To prevent that to happen, it can be combined with materials that are moisture resistant. Kevlar is normally used in space suit as it is fire resistant though kevlar reacts badly with UV light and hence needs to be laminated or coated to be protected from the harsh rays.
Polymer-Polyethylene is partially crystalline as well as amorphous because it has crystalline and amorphous regions. Also it has linear chains so this is the simplest structure compared to a branched or network chain. This can be of an advantage to it over other types of materials as its good toughness and elongation makes it very significant in the engineering industry as it can be moulded or extruded into shape...
There are two popular ways of creating nylon for fiber applications. One, ¡°molecules with an acid (COOH) group on each end are reacted with molecules containing amine (NH©ü) groups on each end.¡± The nylon 6,6 is made in this fashion. The other common way of making nylon fibers is by polymerizing a compound containing an amine at one end and an acid at the other, to form a chain with reoccurring groups of (-NH-[CH©ü]n-CO-)x. If the x=5, the fiber is named nylon 6 (Nylon Fiber).
Vectran is 5 to 10 times stronger than steel. They have another rapidly emerging fiber called spider silk. The resulting spider silk is biosteel. A strand of biosteel can be up to 20 times stronger than a strand of steel. To have a hard body armor, you have to make it out of thick ceramic or metal plates.
Kevlar was first synthesized in 1964 by Stephenie Kwolek in Wilmongton, USA. This products is formed by combining Phenylendiamine and Terephthaloylchlor, the product of bonding these two togetehr is a aromatic polyamide. Kevlar is made up of basic units of monomer bringing together trans conformations. This provides a naturally occuring parallel structure that is ideal to turn into fibers. This product is used in an array of items including underwater cables, brake linings, spaceships, parachutes, ...
Cellulose is an abundant polysaccharide consisting of a β-1, 4 linkage of D-glucose [1,3]. There is an array of applications for cellulose, including, but not limited to: biofuels, reinforcement agents, thickeners, dietary fiber, and even wound care. As of late, cellulose, as a waste product, has been in high demand as a reinforcement agent in synthetic, petroleum-based polymer matrices (petroleum based plastics) [3]. Cellulose I has good flexibility, it is abundant in nature and also biodegradable. Because of its fiber- like structure, it has been compared to carbon nanotubes (CNT’s) [3].
The purpose of this essay is to develop a further understanding of the impacts of social media in regards to the political debate. By looking at the topic of social media and the use rhetoric in response to politics in the 21st century, a deeper understanding of the issue can be established. Social media has become a primary source for the discussion of politics by the average citizen; whether through the sharing of articles, “memes”, advertisements or personal expository statements. As a result, large sums of information and ideas are spread rapidly to a wide variety of subjects. However, much of this information may not be accurate and could be misinterpreted. Consequently potentially misinformed citizens may not be able to make a properly
Steel: (for all intents and purposes) was invented in 1855 by Henry Bessemer(Mary Bellis). Science the amazing innovation that has changed the world incredible things have been made from the material from bridged cables and cross beams to arresting wires on aircraft carriers that stop monumental force and speed. It is truly an amazing martial, but eventually it snaps, breaks or tears due to the separation of the molecules. Also steel is not the most flexible material there is which may sound good for what it is used for, construction. You wouldn’t want the floor to shift from under but, what about in areas that have a consent threat of earthquakes having a material that is rigid when needed and flexible when needed would be an invaluable asset to construction companies in many countries. Also at $600-$900 per ton(Platts Mcgraw hill financial) it isn’t the most inexpensive material that could be chosen. Chemically is there a better material that could be used in the place of steel that is stronger more flexible and can be produced for a cheaper price than the normal steel that we use today? First, the choice of spider silk seems like a great choice. Mother nature seems to be the greatest designer of all made of different sections of proteins of extremely ridged and at the same time extremely elastic strings of proteins, that when braided together are 5 times stronger than steel and relatively free to produce as long as the spiders are kept healthy. What makes the proteins so strong? They are linked together almost like thousands of Lego’s linked together which by its self does not sound very strong, but just take 3 and pull length wise and try to pull them apart, it's almost impossible. The same concept is used in the spider's silk...
Global warming refers to an unequivocal and continuing rise in the average temperature of earth’s climate system (Wikipedia 1). it was discovered a long time ago around the year 1869. Global warming is primarily caused by a problem of too much carbon dioxide (causes of global warming 1). Carbon dioxide (co2) is harmful to many things a very small amount of it can kill a human. Carbon dioxide survives in the atmosphere for a long time. It won’t affect just our generation but it will affect many generations and climates after we die (causes of global warming 1). I believe that climate extremes would trigger a meteorological chaos. Some of the major contributors to global warming are green house gases, particulates and soot ,and solar activty. Thoughs are some major causes but there are still hundreds more left. The green house effect is the process by which absorption and emisson of in fared radiation by gases in a planets atmosphere warm its lower atmosphere and surface. It was proposed by joseph fourier in 1824 and discovered in 1860 by john tyndall. Human activity ever since the industrial revolution has increased the amount of greenhouse gases in the world. (wikipedia 3). One of the first things scientists have learned...