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Kevlar (para-aramid) [2] is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora.Developed by Stephanie Kwolek at DuPont in 1965, [3] [2] [4] the high-strength material was first used commercially in the early 1970s as a replacement for steel in racing tires.
Excellent thermal stability at temperature extremes, water repellency, chemical stability and resistance to petroleum products have made Kevlar KM2 an indispensable asset to the military personnel who use it every day." [1] "Kevlar KM2 fiber is a transversely isotropic material. Its tensile stress–strain response in the axial direction is ...
By 1971, modern Kevlar was introduced. [9] Kwolek learned that the fibers could be made even stronger by heat-treating them. The polymer molecules, shaped like rods or matchsticks, are highly oriented, which gives Kevlar its extraordinary strength. Kwolek continued research of thermotropic Kevlar derivatives containing aliphatic and chlorine ...
Aramid paper is used as electrical insulation materials and construction materials to make honeycomb core. Dupont made aramid paper during the 1960s, calling it Nomex paper. Yantai Metastar Special Paper introduced an aramid paper in 2007, which is called metastar paper. Both Dupont and Yantai Metastar make meta-aramid and para-aramid paper.
Molecular structure of Kevlar Molecular structure of the LCP Vectran [5]. Liquid crystallinity in polymers may occur either by dissolving a polymer in a solvent (lyotropic liquid-crystal polymers) or by heating a polymer above its glass or melting transition point (thermotropic liquid-crystal polymers). [6]
Microfiber fabrics are man-made and frequently used for athletic wear, such as cycling jerseys, because the microfiber material wicks moisture (perspiration) away from the body; subsequent evaporation cools the wearer. Microfiber can be used to make tough, very soft fabric for clothing, often used in skirts, jackets, bathrobes, and swimwear.
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.
Kevlar was initially used as a replacement for steel-belting in tires, and later for use in ropes, gaskets, and automotive and aviation parts. [1] [3] In 1971, Shubin, who was then the Director of Science and Technology for the National Institute for Law Enforcement and Criminal Justice, [4] suggested using Kevlar to replace nylon in bullet ...