Properties of Polymers

Different polymers have different properties, depending on the monomers they are made from and the conditions under which these monomers were joined together.
This means that different polymers have different uses.
- For example, poly(ethene) can be made in low density and high density forms.
Low density poly(ethene) has a structure where the polymer chains are branched and this means that the molecules are arranged randomly.
High density poly(ethene) has less branching of the polymer chains, so the molecules line up much more closely.

Plastics can be put into one of two categories, depending on how they respond when heated.
Thermosoftening plastics melt when they are heated.
Most plastics that we come across in everyday life are thermosoftening plastics.
- This means that they can be recycled, which involves melting them before making a new product.
Thermosoftening plastics do not have covalent bonds between neighbouring polymer molecules, so the molecules can move over each other when heated and the plastic melts.