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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.
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste .
Aramid process diagram World capacity of para-aramid production was estimated at 41,000 t (40,000 long tons; 45,000 short tons) per year in 2002 and increases each year by 5–10%. [ 12 ] In 2007 this means a total production capacity of around 55,000 tonnes per year.
Stephanie Louise Kwolek (/ ˈ k w oʊ l ɛ k /; July 31, 1923 – June 18, 2014) was a Polish-American chemist best known for inventing Kevlar (poly-paraphenylene terephthalamide). ). Her career at the DuPont company spanned more than 40 ye
It soon made its debut in the United States as a replacement for silk, just in time for the introduction of rationing during World War II. Its novel use as a material for women's stockings overshadowed more practical uses, such as a replacement for the silk in parachutes and other military uses like ropes .
The test proved that the STF-Kevlar was able to show a result that was slightly better than the neat Kevlar. The samples demonstrated similar depth, but the neat Kevlar displayed more yarn-pullout and yarn splaying. Observers found that the STF-Kevlar was able to withstand the stab test better than the neat Kevlar.
Synthetic polymers began replacing other chemical binders for soil stabilization in agriculture in the late 20th century. [1] Compared to traditional chemical binders, polymer soil additives can achieve the same amount of strengthening at much lower concentrations – for example, mixtures of 0.5-1% of various biopolymers have strength levels that match or exceed those of 10% cement mixtures ...
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 ...