Bioplastics and sustainability

Former Prime Minister’s Chief Science Advisor Dame Juliet Gerrard talks about the ideas needed to make new materials to replace plastics.

Chief Innovation and Science Officer Dr Elspeth MacRae and Science Leader Biopolymers & Chemicals Dr Florian Graichen from Scion explain the difference between plastics made from renewable and non-renewable sources.

Transcript

Dame Juliet Gerrard

One of the most exciting things about the project has been hearing all the new ideas out there that people are coming up with to solve our plastics problem – lots of little ideas, some big ideas – and all ready at different timeframes. So some of them are ready to go now, and others – like the work that’s going on at Scion – are really ambitious and imagining a whole new future where most of the plastics are made from a new class of materials derived from plant waste.

Kim Hill

Let’s talk about bioplastics. What are they? Why are they called plastics at all?

Dame Juliet Gerrard

People muddle up plastics that can biodegrade that can come from any source with plastics that are made of biological materials. So the Scion programme’s all about making sustainable plastics from any sort of biological materials, but wood would be a focus at Scion.

Kim Hill

Sustainable in the sense that they don’t come from fossil fuels and also in the sense that they can biodegrade.

Dame Juliet Gerrard

So ideally, they’d be plant based in some way and also will biodegrade.

Dr Elspeth MacRae

Plastic’s actually enabled an awful lot of things that we could do. So we wouldn’t have got any spaceships up into, onto the moon without plastics – a lightweight, strong, reliable material. Same with airplane flight – flying around the world right now, you’re flying in plastic pretty much.

So transferring into bioplastics for this means we’ve got to go fast tracking through some of all those developments and finding the right places where bioplastics can substitute.

Dr Florian Graichen

Fundamentally, you have two different ways of making plastics – from petrochemical sources as we know it today, or you can make it from renewable material. And at Scion, we use sugar out of trees for example. We ferment that and turn that then into bioplastics. So the base material does not come from out of the ground, digging deep into the ground, but we’re using what has renewably grown and turn that into a plastic.

Dr Elspeth MacRae

Fossil fuels and fossil materials are actually old trees, they’re actually a material called lignin that holds the tree together, and only that was hundreds and hundreds and thousands of millions of years ago and got compressed in the Earth, and then we got petrol and we got coal out of it for example. 

When we use those into petroleum plastics and then degrade them, we add CO₂ to the atmosphere – new CO₂. When we use the bioplastics, we’re actually using the material – the CO₂ that’s in the atmosphere – to make our bioplastics, so we’re not adding to the whole system and that’s why they’re better for the environment, and as well as that, we can also manage what we do with them and how we get rid of them at the end of life.