Alternatives to plastic? Friday 7, 2019
New research has just been released looking into the potential for developing environmentally friendly plastic alternatives. And it looks like the answers are lying with sulfur polymers! Olivia Holdsworth spoke to scientist Dr Justin Chalker about this research.You can find that interview here, below is a write up by Isla Christensen.
Olivia starts by asking what prompted this study.
Dr Justin Chalker: Our lab and collaborators are interested in designing new and useful materials that are made from sustainable resources. So think about sustainable plastics, rubber and ceramics that are made from things that are renewable or even waste materials, but also materials that can be generally recycled. We are working towards a future in which we can have all the advantages of the useful things that we get from polymers and plastics, but doing that in a sustainable way that doesn't harm the environment.
With approximately eight million pieces of plastic pollution finding their way into our oceans everyday. Dr Chalker explains the importance of this research.
There is a worldwide issue of plastic pollution where you've seen islands of plastics floating around in the ocean and it causes serious harms to ecosystems, and so it's important to design new types of plastics that won't persist in the environment, that can be generally recyclable, and that are prepared from recycled material. For instances, we've made many of our new types of polymers from plant oils such as canola oil, we can even use waste cooking oil to make these materials. Our other key component to this new type of recyclable material is sulfur, which is highly abundant geologically and is also a byproduct of petroleum refining. There are literally mountains of sulfur around the planet ready to be used for something important and so we hope that this will the first step in that direction.
With a global shift in the recycling market, New Zealand's plastic export to China was shut down in 2018. Statistics NZ reports that In 2017, China purchased almost $26 million of waste and recyclables from New Zealand. Current procedures have resulted in large stockpiles of plastics around the country. Olivia asked about the commercial viability of this new sulfa based plastic which would help with our plastic waste.
The types of material that we are making are currently being tested in a variety of different applications, we've made these materials to capture mercury pollution from air, water, and soil. We've used these materials to clean up oil spills, and other groups around the world have shown that these high sulfur content materials can be used as captions for batteries, high end optics for infrared imaging, (so think night vision lenses). Now how will this affect the future of plastics and polymers? Well this is just the first step, we can’t say that these materials will replace all the different types of plastics, but the first step is important because we can demonstrate that you can control these properties and you can design these materials to be functional replacements for traditional plastics which are made from petroleum resources. So even though the chemical composition is quite different we can now tunein properties to give these materials a particular hardness and flexibility, and even a particular colour. The control and design principles are critical in making sure that we can replace plastics that can be recycled.
The future of sustainable sourced materials is exciting. Dr Chalker explains what the next steps are in the process of his research.
We have a fews lines of research ongong. One important aspect is to learn how to scale these materials up. Because if you want them to be building blocks for many useful things, you'll have to make them on the tonne scale. In the first instance we are making hundreds of grams but in some cases we have been preparing many kilograms of these materials and that's quite important to be able to apply the materials. We've also used these material in agriculture for low release fertilizers. In order to realise the commercial reality we need to make them on a larger scale reliably and safely.
So when can we expect to be purchasing and using these materials? Perhaps a lot sooner than you expect.
We are already in the process of working to commericialse on of these polymers. One application that we see moving forward quite rapidly is the polymer we have made from canola oil, (even waste cooking oil), and sulfur. It has a rubbery consistency and is excellent at removing mercury from air or contaminated water.
Photo credit: DW