Researchers have created a plant-based, sustainable, scalable material that could replace single-use plastics in many consumer products.

The researchers, from the University of Cambridge, created a polymer film by mimicking the properties of spider silk, one of the strongest materials in nature. The new material is as strong as many common plastics in use today and could replace plastic in many common household products.

 Professor Tuomas Knowles in Cambridge’s Yusuf Hamied Department of Chemistry explained:

“This is the culmination of something we’ve been working on for over ten years, which is understanding how nature generates materials from proteins.

“We didn’t set out to solve a sustainability challenge — we were motivated by curiosity as to how to create strong materials from weak interactions.”

The material was created using a new approach for assembling plant proteins into materials which mimic silk on a molecular level. The energy-efficient method, which uses sustainable ingredients, results in a plastic-like free-standing film, which can be made at industrial scale. Non-fading ‘structural’ colour can be added to the polymer, and it can also be used to make water-resistant coatings.

The material is home compostable, whereas other types of bioplastics require industrial composting facilities to degrade. In addition, the Cambridge-developed material requires no chemical modifications to its natural building blocks, so that it can safely degrade in most natural environments.

The new product will be commercialised by Xampla, a University of Cambridge spin-out company developing replacements for single-use plastic and microplastics. The company will introduce a range of single-use sachets and capsules later this year, which can replace the plastic used in everyday products like dishwasher tablets and laundry detergent capsules.

The material has a performance equivalent to high performance engineering plastics such as low-density polyethylene. Its strength lies in the regular arrangement of the polypeptide chains, meaning there is no need for chemical cross-linking, which is frequently used to improve the performance and resistance of biopolymer films. The most commonly used cross-linking agents are non-sustainable and can even be toxic, whereas no toxic elements are required for the Cambridge-developed technique.

Dr Marc Rodriguez Garcia, a postdoctoral researcher in Knowles’ group who is now Head of R&D at Xampla said:

“The key breakthrough here is being able to control self-assembly, so we can now create high performance materials.

“It’s exciting to be part of this journey. There is a huge, huge issue of plastic pollution in the world, and we are in the fortunate position to be able to do something about it.”

The results are reported in the journal Nature Communications.