Plastics are the most produced and widely used material on the planet. Approximately 380 million tons of plastic, mostly undegradable, are produced every year.
Undegradable plastics take hundreds of years to degrade in nature due to the stable long polymer chains.
Such a slow progression of plastic waste degradation is causing environmental pollution.
For this reason, Yale School of Environment (YSE) professor Yuan Yao and Liangbing Hu, a professor at the Center for Materials Innovation from the University of Maryland formed a research team to create a high-quality bioplastic that shows promise for producing more sustainable and durable plastics.
Over the years, efforts to switch from petrochemical plastics to recyclable and biodegradable plastics have proven challenging.
The production process is more expensive, requires toxic chemicals (that will lead to environmental pollution), and the water stability and mechanical strength is often insufficient. But Yao and her team have made a breakthrough, using wood by-products.
The researchers published a study in Nature Sustainability which outlines the process of deconstructing the porous matrix of natural wood into a slurry. Yao and her team used a wood powder, a residue usually discarded as waste in lumber mills, to create the slurry mixture.
This powder functions to deconstruct the loose, porous structure of the powder with a biodegradable and recyclable (DES) deep eutectic solvent.
The resulting mixture features nanoscale entanglement and hydrogen bonding between the regenerated cellulose micro/nanofibrils and lignin which contributes to its high stability when holding liquids, high solid content, high mechanical strength, high viscosity, and high UV-light resistance.
The material’s strength demonstrates a unique balance between durability and degradability, which is lacking in hydrophilic cellulose and conventional plastic products. Additionally, this material can be recycled or safely biodegraded in the natural environment.
This is good news for every plastic company in Malaysia. To ascertain her work, Yao led a comprehensive life cycle assessment to test the environmental impacts of the bioplastic against conventional plastics.
First, when the researchers compared this material with petroleum-based plastics and other biodegradable, this bioplastic can be broken down by microorganisms in the soil, which results in a lower life-cycle environmental impact.
Additionally, sheets of the bioplastic were buried in soil, amazingly, fracturing occurred just after two weeks. And after just three months, the biodegradable plastic was completely degraded.
Moreover, according to researchers, “mechanical stirring” can be employed to break down bioplastic into the slurry allowing for the DES to be recovered and reused.
This is what Yao thought about the idea, “That, to me, is what really makes this plastic good: It can all be recycled or biodegraded,” said Yao. “We’ve minimized all of the materials and the waste going into nature.”
On the large scale, Yao’s solution could require the usage of massive amounts of wood which could pose a serious threat to land management, forestry and wildlife, climatic change, as well as our ecosystems.
Well, Yao is much aware of this which is why the team continues to investigate the potential impact on forests, linking the wood manufacturing process with the growth cycle of forests.
Now, Yao and her team have begun working with forest ecologists to design forest simulation models if the manufacturing of this bioplastic is scaled up.
She embraces this rare opportunity to collaborate with foresters as they jointly integrate interdisciplinary approaches from the fields of sustainable engineering, industrial ecology, and systems modelling to develop techniques that facilitate more sustainable engineering approaches and policies.
The process of converting plastics into recyclable and biodegradable plastic bags requires the use of wood by-products. In case the production of this bioplastic is increased, it could necessitate the use of enormous amounts of wood, which could pose a significant threat to the ecosystem at large.
While plastic companies in Malaysia are closely observing the trend, Yao and the research team are examining the environmental and economic impacts of industrial processes using emerging technologies.
According to Yao, “There are many people who have tried to develop these kinds of polymers in plastic, but the mechanical strands are not good enough to replace the plastics we currently use, which are made mostly from fossil fuels.” “We’ve developed a straightforward and simple manufacturing process that generates biomass-based plastics from wood, but also plastic that delivers good mechanical properties as well,” Yao was quoted as saying.
