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Name the polymers used in (l) bullet vests (ii) protective clothing for fire- fighters (iii) bulttet proof windows or crash helmets. |
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Answer» Solution :(i) KEVLAR is a polymide obtained by condensation copolymerization of terephthalic acid and p-phenylenediamine (1,4-diaminobenzene).The fibres of this polymer are so strong that they are used to MAKE light weight bullet -proof vests. (ii) NOMEX uis a polyamide made from m-phthalic acid and m-diaminobenzene. it is known for it is fire- resistant properties and is used in PROTECTIVE clothing for fire- fighters, astronauts ,and race - car drivers. (iii) Lexan is a polycarbonate3 (or a polyester) and is obtained by condensation of diethyl carbonate and bisphenol-A. It has unsaually highe impact STRENGTH and is used for bullet -proof windows and safety or crash helmets. |
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