Sustainable Packaging : Cambridge scientists posit ‘vegan spider silk’ as plastic solution
Researchers at the University of Cambridge have found a way to produce plant protein-based plastic.
Mimicking spider silk, the plastic-like film comes with the distinct advantage of being home compostable, meaning that it does not require industrial conditions to degrade. The energy-efficient production method of the plastic alternative utilises sustainable materials, resulting in a free-standing film that is inherently suitable for mass production. The customizability of the polymer is further proven by the fact that colour can be added to it, the material also being of use in the production of water-resistant coatings.
As such, said plant-based material may serve to replace single-use plastics in the packaging industry.
The convenience, high functionality and consistently low price point associated with plastic has rendered it practically indispensable for manufacturing purposes. This, in turn, has exacerbated the waste crisis, with 2019 seeing more than 130 million metric tonnes of single use plastics being discarded, burned, buried in landfill or dumped into oceans. In 2018, 46% of 340 million tonnes of plastic waste generated annually could be attributed to single use plastics.
With food demands due to increase, especially in developing countries, plastic packaging waste is set to become an issue of note.
The eco-friendly plastic alternative pioneered by Cambridge researchers could help address these challenges.
Soy protein is an example for a renewable, biodegradable polymer that the research team used in order to render a new material that could compete with conventional plant-based plastics.
After creating a plant-based material of their own, the scientists in question added nanoparticles to it. The addition allows for the production of flexible films, with a material that appears similar to spider silk on a molecular level. Ergo, ‘vegan spider silk’.
After analysis of the film via different techniques such as scanning and transmission electron microscopy, the scientists discovered that the nanoparticles helped improve barrier properties ranging from water permeability and durability to overall strength and stability.
This is noteworthy in so far as the food industry has faced difficulties with phasing out conventional plastics due to specific packaging needs. Properties such as moisture sensitivity, high temperature stability, flexibility and non-permeability to odours and microorganisms are only a few of these. This demand for diverse properties has led to hybrid packaging which in turn has foiled recycling attempts.
Other plant-based biodegradable plastics such as polylactic acid (PLA), polybutylene succinate (PBS), polycaprolactone) (PCL) and polyhydroxyalkanotes (PHAs), which have a significantly lower ecological footprint, do exist, but they come with their own drawbacks-PLA, for instance, is not home compostable whilst PHAs are rendered from expensive industrial processes which limits their potential for mass production.
The proposed vegan spider silk could potentially trump these green plastic alternatives with its environmentally friendly production process, renewable source materials and enhanced properties-all of which put it on equal footing with virgin plastics.