ceramics, polymers, and composites

• most of the glass we use is

  soda lime glass
• how is soda lime glass made

  heating a mixture of sand, sodium carbonate and limestone
• Borosilicate glass is made from

  sand and boron trioxide
• borosilicate glass vs soda lime glass

  borosilicate glass melts at higher temperatures
• clay ceramics (pottery and bricks) are made by

  shaping wet clay and then heating in a furnace
• The properties of polymers depend on

  what monomers they are made from and the conditions under which they are made
• Thermosoftening polymers melt when heated
• Thermosetting polymers do not melt when they are heated
• Low density poly(ethene) properties

  • flexible
  • unreactive
  • can be made into films
• Low density poly(ethene) uses

  most carrier bags, bubble wrap
• High density poly(ethene) properties

  • strong
  • flexible
  • resists shattering
  • resists chemical attack
• Low density poly(ethene) structure 


  a structure where the polymer chains are branched and this means that the molecules are arranged randomly.
• High density poly(ethene) structure

   less branching of the polymer chains, so the molecules line up much more closely.
• Thermosoftening structure

  Thermosoftening plastics do not have covalent bonds between neighbouring polymer molecules, so the molecules can move over each other when heated and the plastic melts.
• Thermosetting plastics structure

  The covalent bonds in the thermosetting plastic are strong and prevent the plastic melting when it is heated
• Most composites are made of

  two materials, a matrix or binder surrounding and binding together fibres or fragments of the other material, which is called the reinforcement
• Composite examples 


  • reinforced concrete - steel - concrete
  • fibreglass - glass fibres - polymer resin
  • carbon dibre reinforced polymer - carbon fibres - polymer resin
  • chipboard - wood chips - resin glue
• reinforced concrete 


  steel and concrete
• fibre glass


  glass fibres and polymer resin
• carbon fibre reinforced polymer

  carbon fibres and polymer resin
• chipboard


  woodchips and resin