One of the useful properties of polymers is that they are unreactive. This means they are suitable for storing food and other substances safely. Unfortunately, this property makes it difficult to dispose of polymers.
Suitable locations for landfill sites are difficult to find. Space in landfill sites is wasted if it is filled with non-biodegradable polymers.
Describe what 'biodegradable' means.
If something is biodegradable, it can be broken down or decomposed by microorganisms.
There are problems with incineration. Waste gases are produced, including:
Recycling reduces the problems of disposal, and also reduces the volume of crude oil used.
PET (polyethylene terephthalate) is a polyester (a plastic). There are two methods to recycle PET:
The flaked PET is not totally pure, so the quality of the recycled material is less than the original polymer. Once the recycled material has been used it cannot be recycled again. It is likely to end up in landfill sites.
The quality of the recycled material is as high as the original material, so it may be recycled again. This reduces the use of raw material (crude oil) and landfill even more than open-loop recycling.