When you think of plastic, what springs to mind? Cheap toys from China? Packaging? Or maybe a plastic bag? Of course you would.
But how about a woolly jumper? Or cornflakes? Or an antique oak wardrobe?
Believe it or not, from a chemist’s perspective all these things are made of the same class of materials: Polymers.
And the distinction between which ones we happen to call “plastics” and which ones we don’t is fairly arbitrary.
Polymers are extremely long repetitive molecules which, in the case of plastics, are primarily made of carbon.
“You take a simple organic molecule and you react it with itself again and again and again,” explains chemistry professor Andrea Sella of University College London.
“A little bit like a bicycle chain, you attach one link, and you click on the next one and the next one and the next one, almost ad infinitum.”
Polymers are a very broad category.
By the 1930s you’ve got get Ginger Rogers dancing in a beautiful white laminate interior” Dr Susan Mossman The Science Museum
As well as plastics, they also include the silicones – based on silicon rather than carbon – used in everything from breast implants to fire retardants.
They even include DNA.
The polymers’ shape is what gives plastics their plasticity, allowing them to be moulded into any shape.
The individual strands “can simply slide past each other” says Sella. “Think of cold spaghetti.”