Thermosetting and Thermoplastic

• Thermoplastic


  Weak bonds between chains
• Thermosetting


  Strong covalent bonds between chains
• Thermoplastic


  1. Weak bonds between chains

  2. Hydrogen bonds, dipole-dipole or dispersion forces

  3. They melt when heated

  4. Which means they can be remoulded or recycled
• Thermosetting


  1. Strong covalent bonds between chains

  2. Covalent bonding – decompose or burn when they are heated

  3. Do not soften because the bonds are too strong

  4. Cannot be recycled or made into new shapes
• Crosslinks


  Formed between polymer chains
• If we have infrequent but long crosslinks


  We can gain flexibility
• Elastomers


  A class of molecule where chains can still move past each other, but will return to their original shape
• The more cross-linking between chains


  The more rigid the polymer
• Infrequent crosslinks


  Provide flexibility