4.1.11 Polymers - dealing with polymer waste

4.1.11 Polymers - dealing with polymer waste

1. Why do we need to deal with polymer waste?

   • Polymers are usually regarded as disposable
   • Addition polymers are saturated organic compounds
     • They are very stable
     • When we finish using them, they do not get attacked by environmental conditions or by microorganisms
       • Plastics can remain chemically unchanged for hundreds of years

2. How are addition polymers made?

   • Made from compounds made available from the processing of crude oil
     • Crude oil is a non-renewable resource and we are using it faster than the natural processes in our planet can amke more

3. Polymer waste

   • Landfill
     • Lareg holes are dug into the landscape,the holes are lined to stop any contaminants seeping into the water table
       • Rubbish is then put into holes and compacted, when the site is full, it is capped and landscaped
     • Advantages
     • Disadvantages
       • After the rubiish is burried,the conditions change from normal to atmospheric to anaerobic and there is often a limited supply of water
         • This reduces the rate of decomposition of biodegrable materials
       • As many plastics are non-biodegradble, the waste does not break down and can become a danger to wildlife
   • Combustion
     • Advantages
       • The gases can be removed by using gas scrubbers, where a base such as CaO neutralises the acidic acids
       • As plastics have a high calorific value, they can be burnt in power stations, the chemical energy transferred can be used to drive turbines and generate electricity
     • Disadvantages
       • Carbon dioxide is a greenhouse gas and is linked to climate change
       • Depending on the plastic, other toxic or polluting gases, like HCl, can be made
     • Plastics are mainly organic and can be burnt
       • AS they contain a large amount of carbon, their combustion releasesn carbon dioxide
   • Combustion with electrical generation
   • Reusing
   • Recycling
   • Using them a organic feedstock
   • Photodegradable polymers
   • Biodegradable polymers