Polymers

• Definition of addition polymerisation:

  Formed from alkenes only form the polymer
• What is required for addition polymerisation?

  • Catalyst
• Properties of polyalkenes:

  • Non-biodegradable - because they are inert due to the absence of any polar bonds
• Definition of condensation polymerisation:

  Polymers formed from condensation reactions between monomers. Producing a molecule of water
• Give an example of 2 condensation polymers:

  • Silk
  • Starch
  • DNA
• What are the 2 main types of condensation polymers:

  • Polyamide
  • Polyesters
• What are polyesters formed from?

  • Dicarboxylic acids
  • Alcohols
• What is required to hydrolise a polyester? What do they break down into?

  • A strong acid or specific enzyme is required
  • Their constituent acid and alcohol
• Are polyesters biodegradable?

  Yes, as they contain a linear, polar bond
• What are polyamides formed from?

  • Dicarboxylic acid
  • Diamine
• What is needed to break a polyamide?

  • A strong acid
  • Or specific enzyme
• Advantages + disadvantages of landfill:

  • + cheap, easy
  • – releases methane (decomposition), release toxins that can contaminate water, requires lots of land
• Advantages + disadvantages of incineration:

  • + uses heat to generate electricity
  • – releases toxic fumes, produces CO2
• Advantages + disadvantages of recycling:

  • + sustainable, saves raw materials, cost less than making products from scratch
  • – expensive, difficult to do, easily contaminated, often cannot be used for the same purpose
• Why does PVC melt at a higher temperature than chlorethane?

  The polymer is larger than chloroethene so has stronger van der waals forces of attraction and needs more energy to break them / overcome them
• Why may a plastesiser be used?

  To make the polymer more malleable so it cam be manipulated easier