Question

Why do thermoplastics soften on heating?

Answer 1

1. Thermoplastics have linear or slightly branched polymer chains.
2. These chains are held together by weak intermolecular forces.
3. On heating, these weak forces are easily overcome, allowing the chains to slide over one another.
4. As a result, thermoplastics soften when heated and harden on cooling.
5. This process is reversible, which makes thermoplastics re-mouldable.