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Give the methods of preparation of PVC and PTFE. Also give their uses. |
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Answer» Solution : Polyvinyl chloride (PVC) and polytetra flouroethylene (PTFE) are two common examples of polyhalo-olefins. 1. Polyvinyl chloride, PVC`(-CH_2-underset(Cl)underset(|)CH-)` . It is an additional polymer obtained by heating VINYL chloride in an insert solvent in the presence of benzoyl peroxide (BPO). `underset("Vinyl chloride")(nCH_2=CHCl)(-CH_2-underset(PVC)underset(Cl)underset(|)CH-)_n` Uses. It is used (i) in the manufacture of RAIN coats, hand BAGS, table cloth, curtain cloth, plastic dolls and vinyl floorings. (ii) as an insulating coating for electrical wires, cables and other electrical goods. (iii) in the manufacture of gramophone RECORDS and hose pipes. 2. Polytetrafluoro ethylene PTFE, Teflon `(-CF_2 -CF_2 -)_n` . It is prepared by heating tetrafluoroethylene under high pressure in the presence of ammonium peroxosulphate `(NH_4)S_2 O_8` as catalyst. `underset("Tetrafluoroethylene")(nCF_2 = CDF_2) underset(Delta, "Pressure")overset((NH_4)_2 S_2 O_8)to underset("Teflon")((-CF_2 - CF_2-)_n)` Uses. It is used (i) for making gaskets, pump packing, valves etc. (ii) for making non-cooking utensils. |
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