Question

Comment on the main structural difference between thermoplastics and thermosetting polymers. What effect does this difference have on their properties?

Answer 1

• Main structural difference: Thermoplastics consist of long linear or slightly branched polymer chains with no permanent covalent crosslinks, while thermosetting polymers form a heavily cross‑linked three‑dimensional network of covalent bonds after curing.

• Effect on properties:

  • Thermoplastics soften and melt on heating, so they are mouldable, ductile, and easier to recycle.
  • Thermosets do not melt when heated, are hard and dimensionally stable, have higher heat and chemical resistance, but are more brittle and cannot be remoulded.