Question

Which of the following statements is correct about the polymer?

• A. It is thermoplastic polymer.
• B. It is thermosetting polymer.
• C. It is used in the manufacture of adhesive.
• D. It is not used in the manufacture of switches and plugs.

Answer 1

Answer: (B), (C)

Phenol - formaldehyde polymers are the oldest synthetic polymers. These are obtained by the condensation reaction of phenol with formaldehyde in the presence of either an acid or a base catalyst. The reaction starts with the initial formation of o- (and/or) p-hydroxymethyl phenol derivatives, which further react with phenol to form compounds having rings joined to each other through –CH2 groups. The initial product could be a linear product – Novolac, used in paints.

Novolac on heating with formaldehyde undergoes cross-linking by elimination of water molecules to form an infusible solid mass called bakelite. It is a thermosetting phenol-formaldehyde resin used for making adhesives.

Hence, the correct options are $\text{B}$ and $\text{C}$