Polymers

• What is addition polymerisation?

  • Joining small molecules (monomers)
  • Forms long chains (polymers)
  • Involves unsaturated monomers (alkenes)
• What happens to the double bonds in unsaturated monomers during polymerisation?

  They open up to form polymer chains
• What is the shorthand way to show polymer chains?

  Using brackets and 'n'
• How do you derive the formula of a polymer from its monomer?

  Put the monomer's formula in brackets with 'n'
• What affects the properties of polymers?

  Arrangement of polymer chains and forces
• What are some properties and uses of common polymers?

  • Poly(ethene): flexible, used for bags
  • Poly(propene): strong, used for crates
  • PVC: tough, used for pipes
  • PTFE: non-stick, used for pans
• What is condensation polymerisation?

  • Involves two different monomers
  • Each monomer has two functional groups
  • Small molecule (e.g., water) is lost during bonding
• What types of monomers form polyesters?

  Dicarboxylic acid and diol monomers
• What forms when dicarboxylic acid and diol monomers react?

  An ester link is formed
• What happens each time an ester link is formed in polyesters?

  A molecule of water is lost
• What are some important naturally occurring polymers?

  • DNA: contains genetic information
  • Proteins: formed from amino acids
  • Carbohydrates: provide energy
• What are the monomers that make up DNA?

  Nucleotides
• What do amino acids form through condensation polymerisation?

  Proteins
• What are carbohydrates used for by living things?

  To produce energy
• What are starch and cellulose made of?

  Smaller units of carbohydrates (sugars)
• What are the environmental impacts of polymer disposal?

  • Over 2 million tonnes of plastic waste yearly
  • Non-biodegradable, sit in landfills for years
  • Need for recycling to minimize damage
• What are polymers made from?

  Crude oil
• Why is crude oil considered a finite resource?

  It will eventually run out
• What happens to the price of crude oil as resources are used up?

  The price increases
• What is one way to delay the depletion of crude oil resources?

  Recycling polymers
• What happens to a lot of plastics during disposal?

  They get dumped in landfill sites
• Why are many polymers difficult to recycle?

  They are too expensive to separate
• What is a major problem with non-biodegradable polymers?

  They sit in landfill for years
• What happens to the price of crude oil products as resources dry up?

  The price will increase.
• Why do we need crude oil besides making plastics?

  It is needed for petrol and heating.
• What dilemma do we face as crude oil resources dry up?

  How to use the remaining oil effectively.
• How can we help delay the problem of dwindling oil resources?

  By recycling our polymers.
• What are the main problems associated with the disposal of polymers?

  • Over 2 million tonnes of plastic waste generated yearly.
  • Need to minimize environmental damage during disposal.
• Where do a lot of plastics end up being disposed of?

  In landfill sites.
• Why are many plastics dumped in landfill sites?

  They are difficult or expensive to recycle.
• What is a consequence of most polymers being non-biodegradable?

  They remain in landfill for many years.
• What are the pros and cons of disposing of polymers by combustion?

  Pros:

  • Produces energy for electricity generation.

  Cons:

  • Toxic gases can be released.
  • Contributes to global warming.
• What toxic gas can be produced from burning PVC?

  Hydrochloric acid (HCl).
• What is a major environmental concern when burning plastics?

  Release of carbon dioxide contributing to global warming.
• What are the advantages of recycling polymers?

  • Reduces non-biodegradable waste.
  • Lowers greenhouse gas emissions.
  • Uses less water and energy.
  • Decreases crude oil demand.
  • Saves energy and creates jobs.
• What are the disadvantages of recycling polymers?

  • Requires separation by type, which is costly.
  • Mixed polymers reduce final product quality.
  • Finite recycling limit decreases strength.
  • Melting releases harmful gases.