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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] |
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] |
Teijin Aramid
Teijin Aramid, formerly known as Teijin Twaron, is a company in The Netherlands that produces various high-strength fibers for industrial purposes, most notably their para-aramid, Twaron. Twaron finds applications in numerous markets, such as automotive (tires, hoses, belts), aerospace, civil engineering, construction, leisure goods (e.g. boats), protective clothing (bullet-, fire- and cut-resistant clothing), optical fiber cables, friction and sealing materials and more. The company has been part of the Japanese Teijin Group since 2000, prior to this they were a division of Akzo Nobel, division Industrial Fibers. Next to Twaron, the company markets Technora, Teijinconex as well. History Twaron is a heat-resistant and strong synthetic fiber, developed in early 1970s by the Dutch company AKZO, division Enka, later Akzo Nobel Industrial Fibers. The research name of the aramid was originally Fiber X, but soon called Arenka. In 1973, Akzo decided to use sulphuric acid (H2SO4) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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] |
Vectran
Vectran is a manufactured fiber, spun from a liquid-crystal polymer (LCP) created by Celanese Corporation and now manufactured by Kuraray. Chemically it is an aromatic polyester produced by the polycondensation of 4-hydroxybenzoic acid and 6-hydroxynaphthalene-2-carboxylic acid. Properties Advantages Vectran's golden fibers are noted for their thermal stability at high temperatures, high strength and modulus, low creep, and good chemical stability. They are moisture-resistant and generally stable in hostile environments. Polyester coating is often used around a Vectran core; polyurethane coating can improve abrasion resistance and act as a water barrier. Vectran has a melting point of 330 °C, with progressive strength loss from 220 °C. Disadvantages Although the tensile strength is similar to Kevlar, Vectran still tends to experience tensile fractures when exposed to significant stress. The wispy, hair-like fibers tend to fray, to easily acquire dirt, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Resistance
A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combined without reacting, they may form a chemical mixture. If a mixture is separated to isolate one chemical substance to a desired degree, the resulting substance is said to be chemically pure. Chemical substances can exist in several different physical states or phases (e.g. solids, liquids, gases, or plasma) without changing their chemical composition. Substances transition between these phases of matter in response to changes in temperature or pressure. Some chemical substances can be combined or converted into new substances by means of chemical reactions. Chemicals that do not possess this ability are said to be inert. Pure water is an example of a chemical substance, with a constant composition of two hydrogen atoms bonded to a si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opportunity (rover)
''Opportunity'', also known as MER-B (Mars Exploration Rover – B) or MER-1, and nicknamed Oppy, is a robotic rover that was active on Mars from 2004 until 2018. ''Opportunity'' was operational on Mars for sols ( on Earth). Launched on July 7, 2003, as part of NASA's Mars Exploration Rover program, it landed in Meridiani Planum on January 25, 2004, three weeks after its twin, '' Spirit'' (MER-A), touched down on the other side of the planet. With a planned 90- sol duration of activity (slightly less than 92.5 Earth days), ''Spirit'' functioned until it got stuck in 2009 and ceased communications in 2010, while ''Opportunity'' was able to stay operational for sols after landing, maintaining its power and key systems through continual recharging of its batteries using solar power, and hibernating during events such as dust storms to save power. This careful operation allowed ''Opportunity'' to operate for 57 times its designed lifespan, exceeding the initial plan by (in Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perseverance (rover)
''Perseverance'' is a car-sized Mars rover designed to explore the Jezero (crater), Jezero crater on Mars as part of NASA's Mars 2020 mission. It was manufactured by the Jet Propulsion Laboratory and launched on July 30, 2020, at 11:50 Coordinated Universal Time, UTC. Confirmation that the rover successfully landed on Mars was received on February 18, 2021, at 20:55 UTC. As of , ''Perseverance'' has been active on Mars for Sol (day on Mars), sols ( days, Earth days, or ) since its landing. Following the rover's arrival, NASA named the landing site Octavia E. Butler Landing. ''Perseverance'' has a similar design to its predecessor rover, ''Curiosity (rover), Curiosity'', although it was moderately upgraded. It carries seven primary payload instruments, nineteen cameras, and two microphones. The rover also carried the mini-helicopter ''Ingenuity (helicopter), Ingenuity'' to Mars, an experimental technology testbed that made the first powered aircraft flight on another plane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condensation Polymerization
In polymer chemistry, condensation polymers are any kind of polymers whose process of polymerization involves a condensation reaction (i.e. a small molecule, such as water or methanol, is produced as a byproduct). Natural proteins as well as some common plastics such as nylon and PETE are formed in this way. Condensation polymers are formed by polycondensation, when the polymer is formed by condensation reactions between species of all Degree of polymerization, degrees of polymerization, or by condensative Chain-growth polymerization, chain polymerization, when the polymer is formed by sequential addition of monomers to an active site in a chain reaction. The main alternative forms of polymerization are chain polymerization and polyaddition, both of which give addition polymers. Condensation polymerization is a form of step-growth polymerization. Linear polymers are produced from bifunctional monomers, i.e. compounds with two reactive end-groups. Common condensation polymer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terephthaloyl Chloride
Terephthaloyl chloride (TCL, 1,4-benzenedicarbonyl chloride) is the acyl chloride of terephthalic acid. It is a white solid at room temperature. It is one of two precursors used to make Kevlar, the other being ''p''-phenylenediamine. TCL is used as a key component in performance polymers and aramid fibers, where it imparts flame resistance, chemical resistance, temperature stability, light weight, and very high strength. TCL is also an effective water scavenger, used to stabilize isocyanates and urethane prepolymers. Preparation Terephthalic acid dichloride is produced commercially by the reaction of 1,4-bis(trichloromethyl)benzene with terephthalic acid: : C6H4(CCl3)2 + C6H4(CO2H)2 → 2 C6H4(COCl)2 + 2 HCl It can also be obtained by chlorination of dimethyl terephthalate. Use TCL is used for making various copolymers and aramid polymers such as Heracron, Twaron and Kevlar: References {{Reflist External links * * Aramid Aramid fibers, short for aromatic 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] |
