Addition Polymers

• The feature that makes a molecule an alkene is a carbon-carbon double bond
• Under the right conditions an alkene's double carbon bond can break and form new bonds with something else
• If we had 3 ethene molecules and all the double bonds opened up, they could then bond with each other. This would form one long chain otherwise known as a polymer.
• There are multiple ways to present an addition reaction. The most efficient way is to draw our monomer becoming our repeating unit.

  
• When drawing addition polymers there are a few key ideas to remember.

  • Draw the bonds of the monomer facing up and down rather than at angles.
  • Draw the repeating unit to have two empty bonds
  • Remember to write the n's which say how many monomers and repeating units there are.
  • Also n will be the same on each side.

  
• Write the equation for the addition polymerisation of butene:

  
• When drawing addition polymerisation, after the carbon double bond, count how many carbons and hydrogens there are after it. For example there may be C2H5, then put this on top of the second carbon.
• You name the polymers by putting the world poly in front of the monomers name. The monomer should be in brackets. For example: Butene ---> poly(butene)
• Addition polymerisation reactions require high pressures and catalysts to work