Thermosoftening and Thermosetting Polymers

• Polymer


  A large molecule formed by joining together a large number of monomers
• Properties of polymers


  • Depend on both the monomer and on the conditions used to make the polymer
• Polymers


  • Low-density polyethylene
  • High-density polyethylene
• Conditions to change polymer properties

  • Reaction temperature
  • Reaction pressure
  • Catalyst
• Thermosoftening polymers


  • Melt when heated, can be reshaped, go back to solid when cooled
  • Polymer chains held together by intermolecular forces
  • Intermolecular forces break when heated, allowing polymer strands to separate
• Thermosetting polymers


  • Do not melt when heated
  • Polymer chains connected by strong cross-links
  • Strong cross-links not broken by heat
• You'll find plenty of questions on the properties of polymers in the revision workbook