PLASTICS

 Plastic is a material made from polymers (long chains of molecules of Carbon and Hydrogen).

They can be classified by its origin into:

1. Natural Plastics: These polymers are found in nature and are derived from plants and animals.

Examples: latex, cellulose, rubber, etc.

2. Synthetic Plastics: these are man-made and obtained from petroleum and its derivates.

Synthetic Plastics are classified as:

- THERMOPLASTICS: you can heat them and mould them as many times as you want. It is very easy to recycle them.

- THERMOSETTINGS: can only be heated and moulded once and the process cannot be repeated. The process to recycle them is more expensive, polluting and difficult.

- ELASTOMERS: they stretch a lot when applying forces and can recover their original shape after suffering huge deformations.

Answer these questions about the video:

1: What is one problem caused by plastic in the ocean?

2: Why was plastic invented?

3: What natural materials were used before plastic?

4: What is plastic mainly made from?

5: How does plastic help protect undersea cables?

6: Why does plastic last a long time?

7: What should people do about plastic use?