Ultra-high molecular weight polyethylene (in English Ultra High Molecular Weight Poly-Ethylene) is a polymer specialized, non-fluid, worked with techniques similar to those of metals; has one atomic mass of 3-6 MDa. 5% yarn in naphthalene or decalin gives a fiber, called Dyneema with one crystallinity by 85% e density of 0.97 g/cm3. This "super-fiber" is used for special applications such as bulletproof clothing, sails, laces; turns out to be 2 times more resistant than kevlar and 15 times more thansteel at the same weight. It represents the lightest and most resistant material on the market. Although it is a linear polymer, its degree of crystallinity is not high (45-60%), and can even be lower than that of LDPE (50-60%).
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