Properties and Uses

Properties and Uses

1. Polymers

   • thermosetting
     • strong covalent bonds (think plugs)
       • covalent cross links- heat has no effect
   • thermosoftening
     • weak intermolecular forces
       • no cross links- can be melted
         • when cooled polymer hardens to new shape
   • plasticised
     • flexible- plasticiser stretches forces, pushing chains apart
   • unplasticised
     • low density- strong im forces make chain rigid

2. polymer properties

   • malleable, strong, weather proof
     • high mp
     • good insulators, cheap abundant
       • can be made into fibres
   • don't biodegrade
     • release co2 when burned
       • use up natural resources
       • danger to animals

3. Nanoscience

   • the science of very small things only a few atoms long
   • longer lasting
   • harder wearing
   • different properties of conduction

4. Types of Reaction

   • Endothermic
     • Gives out heat energy which disperses into surroundings
   • Exothermic
     • take in heat from surroundings
   • BONDS STORE ENERGY
     • energy added to break bonds = endothermic
       • energy released as new bonds= exothermic