Solution to Plastic Pollution (AQA A Level Chemistry)

Disposing of Polymers

• Though poly(alkenes)s are extremely important in everyday such as their use as plastics, the disposal of these polymers is problematic

• Poly(alkenes) are very large alkane molecules which are unreactive and therefore do not undergo any chemical reactions; they are resistant to chemical attack

• Due to their unreactivity, polymers are non-biodegradable and take up to hundreds of years to decompose when dumped in landfill sites

  • Throwing away poly(alkenes) therefore cause the long-term pollution of the environment

• Burning the polymers results in harmful combustion products which again cause the pollution of the environment

Solutions to Plastic Pollution

• Possibly the easiest method to reduce the amount of plastic, is to reuse it rather than throwing it away

• Since polymers have a long chain full of saturated, non polar C-C bonds

• This makes them very unreactive molecules, which is why they are said to be non-biodegradable

  • They cannot be attacked and broken down by biological agents, such as enzymes

• This is what makes throwing plastic away to end up on a landfill such a problem

• Instead of throwing it away or reusing the plastic, you could recycle it

Feedstock Recycling

• This is one possible solution to deal with the excess pollution that is caused by plastic

• This process involves

  • Heating the plastic to a high enough temperature that the polymer bonds break, and monomers are formed

  • The monomers formed are then used to produce new plastics

Mechanical Recycling

• This is a more straight forward type of recycling

• The different types of plastic are separated and washed thoroughly

• Then, they are ground up into small pellets

• The pellets are heated up until they melt, and then remoulded so that they can be used again

Some Issues

• These types of recycling are not perfect solutions

• Some plastics, like poly(propene), can only be heated and reused a number of times

• Each time the plastic is heated, some of the key chains break

• This means that over time, the properties of the plastic are degraded