Question

How are polymers classified on the basis of forces operating between their molecules? To which of these classes does nylon-66 belong?

Answer 1

1. Polymers can be classified by the forces between their chains: weak van der Waals, polar/dipole and hydrogen bonds, or covalent inter‑chain bonds.
2. Weak van der Waals forces allow chains to slide, giving soft, low‑melting thermoplastics and elastic materials.
3. Stronger dipole–dipole and hydrogen bonds hold the chains together, producing stiff, high‑tensile fibres.
4. Covalent inter‑chain links (cross‑links) form rigid, infusible three‑dimensional networks called thermosets.
5. Nylon‑66 is a condensation polymer with amide groups that form regular hydrogen bonds between chains, so it belongs to the fibre class.