Now, a new study provides evidence that hemp could be a substitute for polyethylene in packaging, meaning that the plant could be used in packaging as one of the first major applications of hemp bioplastics.
A research team from Western University (WU), London, Ontario, conducted
The Potential of Hemp-Based Plastics
As the climate crisis continues to loom, and plastic continues to fill landfills and our oceans, researchers note that growing interest in biodegradable and bio-based materials to replace conventional plastics. Authors cite existing options, like polymers based on 2,5-furandicarboxylic acid (FDCA), as proposed alternatives, though these options are often brittle with limited biodegradability.
To test how hemp may fare, the team replaced high-density polyethylene pellets used in conventional plastic with powder from ground-up hemp stems. Researchers then fed the material directly into the manufacturing process used today to produce packaging, without any special technology or additional processes added.
The results revealed that hemp isn’t quite at the same level, when it comes to the strength and malleability of conventional plastics, though it is still stronger and more malleable than other plant-based materials. Researchers also said that the material was still sufficient quality for a number of applications.
The study notes the promise of hemp-derived polymers, stating that the findings “demonstrate a new series of biocomposites … which can be fully sourced from renewable resources and has strong potential for biodegradation in the environment.”
A Potentially World-Changing Material
Elizabeth Gillies, an author of the paper and chemistry professor at WU,
While long-term durability hasn’t been tested, Fillies said that the material should ideally be durable while sitting on store shelves and in the hands of consumers.
“But of course, in the environment, it is actually designed to not be durable and to break down over a period of ideally a few months,” Gillies said.
While large-scale production is still a ways off, Gillies said that the team took mass production into consideration during the initial design process and that the hemp polymer material is meant to be a fairly similar chemical structure.
Protecting the Planet and Navigating Higher Costs
Underscoring these findings is the broader issue of Earth’s ongoing plastic crisis.
Gillies noted the increase in interest over time in plastic substitutes; it was not so much a focus in a broader sense when she first started her work 20 years ago, but she said it’s since become a major area in research.
“The biggest change that I’ve really seen over the course of my career is that companies now are really starting to think about the end life of their materials, and thinking that at some point, probably, they’ll have to be responsible for that,” Gillies said. “So, that’s actually driving a lot of industry investment as well, and of course that’s accompanied by demands by consumers as well, to have more environmentally friendly and degradable products. So it’s a combination of all these players.”
Giving even more weight to the sustainable approach, Gillies also noted that researchers are trying to use waste materials for the substitute, hemp specifically, that would otherwise end up in a landfill. She also explained that hemp simply carries benefits that other materials don’t.
“When it comes to packaging, plastic replaces things like metal and glass. Those are heavy and expensive,” Gillies said. “Depending on the shape, hemp can have a fibrous structure, which works great as a reinforcement for materials.”
She also explained that hemp contains cellulose, which wood also contains, and this can offer a fibrous structure to reinforce materials.
As a material like this potentially goes to market, Gillies said that the cosmetics industry would be a good place to start. She admitted that, at least initially, products packaged with this new material may go for a higher price point, but the cosmetics industry is an ideal industry to tolerate higher-cost products.
The paper notes, “In terms of cost, biomaterials are currently more expensive to produce than plastics, but companies are working to optimize and reduce prices, so costs are expected to decrease in the coming years as these technologies improve.”