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    Kevlar Is A Heat-Resistant and Strong: para

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    Kevlar is a synthetic fiber developed by DuPont in 1965 that is heat-resistant and very strong. It is five times stronger than steel yet also lightweight. Originally used in racing tires as a replacement for steel, Kevlar now has many applications including bulletproof vests, bicycle tires, marching drumheads, and mooring lines due to its high strength to weight ratio. Kevlar is synthesized from chemical reactions between monomers and oriented along the fiber's direction through mechanical drawing which results in its liquid-crystalline behavior and high strength properties.

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    Kevlar Is A Heat-Resistant and Strong: para

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    subham
    13 views1 page
    Kevlar is a synthetic fiber developed by DuPont in 1965 that is heat-resistant and very strong. It is five times stronger than steel yet also lightweight. Originally used in racing tires as a replacement for steel, Kevlar now has many applications including bulletproof vests, bicycle tires, marching drumheads, and mooring lines due to its high strength to weight ratio. Kevlar is synthesized from chemical reactions between monomers and oriented along the fiber's direction through mechanical drawing which results in its liquid-crystalline behavior and high strength properties.

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    ISC CHEMISTRY PROJECT

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    Kevlar

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    Kevlar is a synthetic fiber developed by DuPont in 1965 that is heat-resistant and very strong. It is five times stronger than steel yet also lightweight. Originally used in racing tires as a replacement for steel, Kevlar now has many applications including bulletproof vests, bicycle tires, marching drumheads, and mooring lines due to its high strength to weight ratio. Kevlar is synthesized from chemical reactions between monomers and oriented along the fiber's direction through mechanical drawing which results in its liquid-crystalline behavior and high strength properties.

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    Download as docx, pdf, or txt
    13 views1 page

    Kevlar Is A Heat-Resistant and Strong: para

    Uploaded by

    subham
    Kevlar is a synthetic fiber developed by DuPont in 1965 that is heat-resistant and very strong. It is five times stronger than steel yet also lightweight. Originally used in racing tires as a replacement for steel, Kevlar now has many applications including bulletproof vests, bicycle tires, marching drumheads, and mooring lines due to its high strength to weight ratio. Kevlar is synthesized from chemical reactions between monomers and oriented along the fiber's direction through mechanical drawing which results in its liquid-crystalline behavior and high strength properties.

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    of 1

    Kevlar is a heat-resistant and strong synthetic fiber, related to other aramids such

    as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965,[1][2][3] this high-strength
    material was first commercially used in the early 1970s as a replacement for steel in racing tires.
    Typically it is spun into ropes or fabric sheets that can be used as such or as an ingredient
    in composite materialcomponents.
    Kevlar has many applications, ranging from bicycle tires and racing sails to bulletproof vests,
    because of its high tensile strength-to-weight ratio; by this measure it is five times stronger than
    steel.[2] It is also used to make modern marching drumheads that withstand high impact. When used
    as a woven material, it is suitable for mooring lines and other underwater applications.
    Kevlar is synthesized in solution from the monomers 1,4-phenylene-diamine (para-
    phenylenediamine) and terephthaloyl chloride in a condensation reaction yielding hydrochloric
    acid as a byproduct. The result has liquid-crystalline behavior, and mechanical drawing orients the
    polymer chains in the fiber's direction. Hexamethylphosphoramide (HMPA) was the solvent initially
    used for the polymerization, but for safety reasons, DuPont replaced it by a solution of N-methyl-
    pyrrolidone and calcium chloride.

    5.1. SuperbProperties of Kevlar ●It is strong but relatively light. ●Unlike most plastics it does not melt:
    it's reasonably good at withstanding temperatures and decomposes only at ~450°C (850°F). ●Kevlar can
    be ignited but burning usually stops when the heat source is removed. ●Very low temperatures have no
    effect on Kevlar. There is no appreciable embrittlement or degradation down to -196°C (-320°F), which
    makes it excellent for Arctic conditions. ●Like other plastics, long exposure to ultraviolet light (in
    sunlight, for example) causes discoloration and some degradation of the fibres. Kevlar can resist attacks
    from many different chemicals, though long exposure to strong acids or bases will degrade it over time.
    ●Kevlar remains virtually unchanged after exposure to hot water for more than 200 days and its
    properties are virtually unaffected by moisture.

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