Mike Jackson, USA asked:
As far as I know plastics are synthesised from starting ingredients like oil. Will it be difficult to make plastics as well as oil supplies are depleted in the future? I can imagine a world where we are less dependent on energy perhaps but do you think we’ll still need them for plastics and will that every go away?
Most of the plastics that we use at the moment are manufactured from oil. You break up long chains, and you tend to get small gases, things like ethane. Out of an oil refinery you can cook up crude oil very hot and get some useful gases. You can then react them together and then stick them together and the little units stick together. They form long polymers which is what pretty all plastics are made of.
There has been a lot of research recently into other ways of making plastics in case we do run out of oil: using biological foodstuffs mostly and also so you can make plastics which are more biodegradable because we’re making plastics from oil in a way very alien to organic processes. Organic things can’t break them down very well. There have been various things including genetically engineering bacteria to produce precursors to making plastics or even whole plastics themselves. If you mash up a bacteria extracts with plastic you can get a beautiful plastic out.
These plastics are doing the same job if not slightly better because they aren’t going to persist in the environment and cause huge pollution like normal plastics do.