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Kevlar
Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s as a replacement for steel in racing tires. It is typically spun into ropes or fabric sheets that can be used as such, or as an ingredient in composite material components. Kevlar has many applications, ranging from bicycle tires and sailcloth#Kevlar, racing sails to bulletproof vests, due to its high Specific strength, tensile strength-to-weight ratio; by this measure it is five times stronger than steel. It is also used to make modern marching drumheads that withstand high impact, and for Mooring, mooring lines and other underwater applications. A similar fiber, Twaron, with the same chemical structure was developed by Akzo in the 1970s. Commercial production started in 1986, and Twaron is manufactured by Teijin Aramid. History Poly- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stephanie Kwolek
Stephanie Louise Kwolek (; July 31, 1923 – June 18, 2014) was an American chemist best known for inventing Kevlar (poly-paraphenylene terephthalamide). Her career at the DuPont company spanned more than 40 years. For her discovery, Kwolek was awarded the DuPont company's Lavoisier Medal for outstanding technical achievement. As of August 2019, she was the only female employee to have received that honor.Dan Samorodnitsky"Meet Stephanie Kwolek, the woman who gave us bulletproof vests and yoga pants"'' Massive Science, July 31, 2019.'' In 1995 she became the fourth woman to be added to the National Inventors Hall of Fame. Kwolek won numerous awards for her work in polymer chemistry, including the National Medal of Technology, the IRI Achievement Award and the Perkin Medal. Early life and education Kwolek was one of two children born to Polish immigrant parents in the Pittsburgh suburb of New Kensington, Pennsylvania, in 1923. The grade school she attended was small enough ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulletproof Vest
A bulletproof vest, also known as a ballistic vest or bullet-resistant vest, is a type of body armor designed to absorb impact and prevent the penetration of firearm projectiles and explosion fragments to the torso. The vest can be either soft—as worn by police officers, security personnel, prison guards, and occasionally private citizens to protect against stabbing attacks or light projectiles—or hard, incorporating metallic or para-aramid components. Soldiers and police tactical units typically wear hard armour, either alone or combined with soft armour, to protect against rifle ammunition or fragmentation. Additional protection includes trauma plates for blunt force and ceramic inserts for high-caliber rounds. Bulletproof vests have evolved over centuries, from early designs like those made for knights and military leaders to modern-day versions. Early ballistic protection used materials like cotton and silk, while contemporary vests employ advanced fibers and cera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailcloth
Sailcloth is cloth used to make sails. It can be made of a variety of materials, including natural fibers such as flax, hemp, or cotton in various forms of sail canvas, and synthetic fibers such as nylon, polyester, aramids, and carbon fibers in various woven, spun, and molded textiles. History Western traditions Viking longships used wool for sailcloth. The cloth was woven in one of three ways, according to locality and tradition: plain weave with individual threads going over and under each other, three-shaft twill with two threads going over and under at each cross thread, and four-shaft twill with thread interwoven with two threads at a time in either direction. Such was the practice from the 11th through the 14th centuries. Doek is Dutch for cloth, which evolved into the English word "duck" in reference to sail canvas. Duck was typically made from cotton or linen (flax), with some use of hemp. These natural fibers have poor resistance to rot, UV light and water absor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lester Shubin
Lester D. Shubin (September 27, 1925 – November 20, 2009) was an American research chemist who developed Kevlar for the use in ballistic vests. Kevlar's use in ballistic vests was later expanded for use in all types of personal armor. Life Shubin was born in Philadelphia, Pennsylvania, and graduated from South Philadelphia High School in 1943. He served in the U.S. Army within France and Germany during World War II. He was among the troops that liberated the Dachau concentration camp. "He didn't talk about it until the last few years," his son Harry Shubin said. "It completely changed his life. He didn't follow rules if they didn't make sense to him. And he'd explain his thinking to you, and by the time he was done, you agreed." After the war, Shubin worked as a chemist and joined the U.S. Department of Justice in 1971. Shubin worked for many years at the National Institute of Justice ("NIJ"), the federal agency designated with research and development in the field of law enfor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aramid
Aramid fibers, short for aromatic polyamide, are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic-rated bulletproof vest, body armor cloth, fabric and ballistic composites, in marine cordage, marine hull reinforcement, as an asbestos substitute, and in various lightweight consumer items ranging from phone cases to tennis rackets. The chain molecules in the fibers are highly oriented along the fiber axis. As a result, a higher proportion of the chemical bond contributes more to fiber strength than in many other synthetic fibres in the world. Aramids have a very high melting point (>). Common aramid brand names include Kevlar, Nomex, and Twaron. Terminology and chemical structure The term ''aramid'' is shortened from ''aromatic polyamide''. It was introduced in 1972, accepted in 1974 by the Federal Trade Commission of the USA as the name of a generic category of fiber distinct from nylon, and adopted by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nomex
Nomex is a trademarked term for an inherently flame-resistant fabric with meta-aramid chemistry widely used for industrial applications and fire protection equipment. It was developed in the early 1960s by DuPont and first marketed in 1967. The fabric is often combined with Kevlar to increase its resistance for breakage or tear. Properties Nomex and related aramid polymers are related to nylon, but have aromatic backbones, and hence are more rigid and more durable. Nomex is an example of a '' meta'' variant of the aramids (Kevlar is a '' para'' aramid). Unlike Kevlar, Nomex strands cannot align during filament polymerization and have less strength: its ultimate tensile strength is . However, it has excellent thermal, chemical, and radiation resistance for a polymer material. It can withstand temperatures of up to . Production Nomex is produced by condensation reaction from the monomers ''m''-phenylenediamine and isophthaloyl chloride. It is sold in both fiber and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer Chemistry
Polymer chemistry is a sub-discipline of chemistry that focuses on the structures, chemical synthesis, and chemical and physical properties of polymers and macromolecules. The principles and methods used within polymer chemistry are also applicable through a wide range of other chemistry sub-disciplines like organic chemistry, analytical chemistry, and physical chemistry. Many materials have polymeric structures, from fully inorganic metals and ceramics to DNA and other biological molecules. However, polymer chemistry is typically related to synthetic and organic compositions. Synthetic polymers are ubiquitous in commercial materials and products in everyday use, such as plastics, and rubbers, and are major components of composite materials. Polymer chemistry can also be included in the broader fields of polymer science or even nanotechnology, both of which can be described as encompassing polymer physics and polymer engineering.Hans-Heinrich Moretto, Manfred Schulz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twaron
Twaron (a brand name of Teijin Aramid) is a para-aramid, high-performance yarn. It is a heat-resistant fibre, helps in ballistic protection and cut protection. Twaron was developed in the early 1970s by the Dutch company Akzo Nobel's division Enka BV, later Akzo Industrial Fibers. The research name of the para-aramid fibre was originally Fiber X, but it was soon called Arenka. Although the Dutch para-aramid fiber was developed only a short time after DuPont's Kevlar, the introduction of Twaron as a commercial product came much later than Kevlar due to financial problems at the Akzo company in the 1970s. As of 2000, Twaron had become a global material and had been integrated into the global markets. Twaron has been around for over 30 years. History This is a chronology of the development of Twaron: * In 1960s a research program starts for "Fiber X." * In 1972 the ENKA Research laboratory develops a para-aramid called Arenka. * In 1973 Akzo decides to use sulfuric acid (H2SO4) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Material
A composite or composite material (also composition material) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a material with properties unlike the individual elements. Within the finished structure, the individual elements remain separate and distinct, distinguishing composites from mixtures and solid solutions. Composite materials with more than one distinct layer are called ''composite laminates''. Typical engineered composite materials are made up of a binding agent forming the ''matrix'' and a Filler (materials), filler material (particulates or fibres) giving ''substance'', e.g.: * Concrete, reinforced concrete and masonry with cement, lime or Mortar (masonry), mortar (which is itself a composite material) as a binder * Composite wood such as glulam and plywood with wood glue as a binder * Reinforced plastics, such as fiberglass and fibre-rein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technora
Technora is an aramid that is useful for a variety of applications that require high strength or chemical resistance. It is a brand name of the company Teijin Aramid. Technora was used on January 25, 2004 to suspend the NASA Mars rover '' Opportunity'' from its parachute during descent. It was also later used by NASA as one of the materials, combined with nylon and Kevlar, making up the parachute that was used to perform a braking manoeuvre during atmospheric entry of the rover '' Perseverance'' that landed on Mars on February 18, 2021. Production Technora is produced by condensation polymerization of terephthaloyl chloride (TCl) with a mixture of p-phenylenediamine (PPD) and 3,4'-diaminodiphenylether (3,4'-ODA). Stephanie Kwolek, Hiroshi Mera, Tadahiko Takata “High-Performance Fibers” in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. The polymer is closely related to Teijin Aramids's Twaron or DuPont's Kevlar Kevlar (para-aramid) is a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nylon
Nylon is a family of synthetic polymers characterised by amide linkages, typically connecting aliphatic or Polyamide#Classification, semi-aromatic groups. Nylons are generally brownish in color and can possess a soft texture, with some varieties exhibiting a silk-like appearance. As Thermoplastic, thermoplastics, nylons can be melt-processed into fibres, Thin film, films, and diverse shapes. The properties of nylons are often modified by blending with a variety of additives. Numerous types of nylon are available. One family, designated nylon-XY, is derived from diamines and dicarboxylic acids of carbon chain lengths X and Y, respectively. An important example is nylon-6,6 (). Another family, designated nylon-Z, is derived from amino acid, aminocarboxylic acids with carbon chain length Z. An example is nylon-[6]. Nylon polymers have extensive commercial applications, including uses in textiles and fibres (such as apparel, flooring and rubber reinforcement), molded components fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mooring
A mooring is any permanent structure to which a seaborne vessel (such as a boat, ship, or amphibious aircraft) may be secured. Examples include quays, wharfs, jetties, piers, anchor buoys, and mooring buoys. A ship is secured to a mooring to forestall free movement of the ship on the water. An ''anchor mooring'' fixes a vessel's position relative to a point on the bottom of a waterway without connecting the vessel to shore. As a verb, ''mooring'' refers to the act of attaching a vessel to a mooring. The term likely stems from the Dutch verb ''meren'' (to ''moor''), used in English since the end of the 15th century. Permanent anchor mooring These moorings are used instead of temporary anchors because they have considerably more holding power. They cause lesser damage to the marine environment, and are convenient. Where there is a row of moorings they are termed a tier. They are also occasionally used to hold floating docks in place. There are several kinds of moor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
