Additional polymerisation

• What happens if alkanes are polymerised?

  They form poly alkenes only
• What is an example of addition polymer

  ethene to poly ethene
• What shape is the repeating unit always based on 


  This

  
• When during a repeating unit, what must you do?

  Draw the bonds to extend past the brackets
• Why is the poly(alkene) less reactive than the alkene

  It does not have a double bond it has a longer chain and is fully saturated
• How do you identify a repeating unit?

  — choose two carbon atoms

  — based on the ethene shape

  — find the four atoms/ groups attached
• What a typical use of PVC

  PLASTIC BAGS
• How are the properties of PVC modified using a plasticizer

  They become more flexible and soft as the plasticiser makes the chains further apart so they slide over eachother