A polymer is a very large molecule
Polymers are very large molecules made from many repeating units. Think of a long chain. Strong covalent bonds join atoms along each chain.
Lesson 2.6 · AQA Combined Science
Polymers and repeating units
Why polymers are usually solids
Because the molecules are very large, the intermolecular forces between polymer chains are relatively strong compared with those between small molecules. More energy is needed to overcome these forces, so polymers are usually solid at room temperature. Covalent bonds along the chain are also strong.
Read a repeating-unit drawing
The brackets enclose a unit that repeats. The n means a large number of repeats. Bonds pass through the brackets to show the chain continues. This example is poly(ethene); each repeat contains two carbons and four hydrogens.
Keep the two attractions separate
Use covalent bonds within a chain and intermolecular forces between chains. A polymer is not a giant ionic lattice. Most ordinary plastics do not conduct because they lack mobile ions or delocalised electrons.
Remember
Polymers have strong covalent bonds along chains and intermolecular forces between chains. n means many repeats.
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