9.3.4 Problems with Polymers | Edexcel GCSE Chemistry Revision Notes 2018

Problems with Polymers

Polymers are formed by the joining up of many small molecules with strong covalent bonds
This makes polymers unreactive and chemically inert so they don’t easily biodegrade

Disposal of polymers, Edexcel IGCSE Chemistry

Disposal of polymers is an environmental problem

Waste polymers are disposed of in landfill sites but this takes up valuable land, as polymers are non-biodegradable so micro-organisms such as decomposers cannot break them down
This causes sites to quickly fill up

Polymers release a lot of heat energy when they burn and produces carbon dioxide which is a greenhouse gas that contributes to climate change
Polymers that contain chlorine such as PVC release toxic hydrogen chloride gas when burned
If incinerated by incomplete combustion, carbon monoxide will be produced which is a toxic gas

Polymers can be recycled but different polymers must be separated from each other
This process is difficult and expensive

Recycling is a more economically viable process than manufacturing from scratch
It decreases the use of crude oil which allows it to be kept for other purposes
It is better for the environment as plastic waste is being collected and reused, hence recycling reduces the emissions of greenhouse gases and other toxic gases produced during the manufacturing process
It also reduces the amount of landfill sites needed
Recycling is itself an entire industry which creates employment and economic growth

Sorting plastics by type of polymer is a tedious and labour intensive process which is costly
Recycling counts on what is collected in as the raw material, therefore production of certain types of polymers may not be possible due to a lack of starting ingredients
Melting polymers produces toxic gases that are harmful to plants and animals
Polymers can only be recycled a number of times before they lose their properties and become useless
Recycling runs the risk of mixing different polymers together, which again will affect their properties. This is particularly risky for polymers designed for specialist use such as aircraft or automobile parts, where safety is of utmost importance

Polymer Types, Edexcel GCSE Chemistry

Diagram showing the categories into which they must be sorted before recycling

You should be able to evaluate the pros and cons of recycling polymers, given appropriate information.