How many of the following polymers given, come under the category of condensation polymers? Bakelite, Teflon…

1. 4
2. 3
3. 5
4. 6

Solution

The given polymers are formed as follows : Bakelite These are made by the condensation reaction of formaldehyde and phenol in presence of either an acid or base, as a catalyst. It involves the formation of methylene bridges in ortho/ para position.
On heating with formaldehyde, novolac undergoes cross-linking to form an infusible solid mass, which is known as bakelite.
It is a condensation polymer. Teflon It is prepared by heating tetrafluoroethylene at high pressure in the presence of peroxides or ammonium peroxo sulphate $\left[\left(\mathrm{NH}_4\right)_2 \mathrm{~S}_2 \mathrm{O}_8\right]$ catalyst. It is chemically inert and resistant to attack.
It is an addition polymer. Nylon-6 or Perlon It is also known as perlon and is obtained from the monomer caprolactum. This caprolactum is obtained from cyclohexane.
Here, in both monomeric species, there are 6 carbon atoms each. Dacron or Terylene It is a polymer obtained by condensation reaction between ethylene glycol and terephthalic acid at $425-475 \mathrm{~K}$ in the presence of zinc acetate antimony trioxide catalyst.
Nylon-6 and dacron both are condensation polymers. Polyisoprene
It also an addition polymer. Melamine In this particular reaction, melamine and formaldehyde copolymerise to give another polymer
Thus, is a condensation polymer. Neoprene It is also called polychloroprene and formed by the free radial polymerisation of chloroprene and has superior resistance to vegetable and mineral oils.
It is an addition polymer. Hence, among the given polymers, we have four (4) condensation-polymers and option (a) is the correct answer.

Asked in: AP EAMCET 2019 (21 Apr Shift 1)

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