polymers

• what afre polymers?

  large, chain-like molecules that can extend for thousands of atoms.
• what are polymers held together by?

  • strong covalent bonds between atoms in molecules.
  • weak intermolecular forces between moelcules.
• why do polymer's intermolecular forces add up to be quite strong, despite being weak?

  because of the large size of polymer molecules.
• what state are polymers at room temperature usually?

  solid
• why do many polymers melt easily despite being solid at room temperature?

  because the weak intermolecular forces remain less strong than chemical bonds.
• what are the monomers used in addition polymerisation?

  alkenes
• why are alkenes the monomers used in addition polymerisation?

  because the C=C double bonds in alkenes can open up to allow multiple alkenes to join together.
• what are the products of addition polymerisation?

  the polymer is the only product meaning that the repeating unit has exactly the same atoms as the monomer.
• what is the product when ethene monomers undergo addition polymerisation?

  poly(ethene)
• what is the product when propene monomers undergo addition polyermerisation?

  poly(propene)
• what is the product when tetrafluoroethene monomers undergo addition polymerisation?

  poly(tetrafluoroethene) also known as PTFE
• what is the product when chloroethene monomers undergo addition polymerisation?

  poly(chloroethene) also known as PVC
• what is a covalent bond?

  involves 2 atoms sharing 1 or more electron pairs. The covalent bonds between atoms in polymers are strong.
• what are intermolecular forces?

  Forces of attraction between molecules.
• what is addition polymerisation?

  the joining together of numerous alkene monomers to produce one long-chain polymer.
• what is condensation polymerisation?

  the joining together of 2 functional groups to produce larger polymers as well as small molecule by-products (eg H20).
• how is the simplest type of condensation polymer produced?

  by combining 2 monomers that each have identical functional groups.
• why do polymers cause wastage problems?

  they do not biodegrade (break down naturally).
• why are landfill sites a problem to do with polymers?

  when plastics are added to a landfill site, the land becomes polluted. We have to make new sites to bury plastic all the time.
• why is combustion a problem to do with polymers?

  when we combust plastics to generate energy, many toxic and acidic gases gases are released into our atmosphere. For example, carbon dioxide is produced, which contributes to global warming.
• why is difficulty recycling a problem to do with polymers?

  plastics can be difficult to recycle. There are many types of plastic and, before they can be recycled, they must be sorted in to their different types. Once they are sorted, they can be melted down and reshaped.
• why is cost a problem to do with polymers?

  all of these processes can be costly.
• what are the advantages of polymers?

  • synthetic polymers are made from crude oil, which is a finite resource so by recycling we reduce the amount of oil being used.
  • synthetic polymers release energy when burned which can be used to heat homes and generate electricity.
• why is polymers not being biodegradable sometimes a good thing?

  they don't rot away and so are recycled instead so they don't take up space in landfill sites.
• what are synthetic plastics made from?

  crude oil
• what monomers combine to make proteins?

  Amino acids
• what monomers combine to give starch and cellulose?

  sugars
• what are examples of naturally occuring polymers?

  • proteins
  • starch
  • DNA
  • cellulose