Upcoming decades are estimated to witness a rise in plastic production and usage, thereby stimulating plastic pollution. Researchers are striving to find a solution to mismanaged plastic products to reduce their environmental impacts.
Scientists at the Wood Hole Oceanographic Institution (WHOI) have been utilizing the principles of green chemistry and engineering to prepare plastics that have the shortest lifespans. As straws and food wrappers contribute most to plastic pollution, researchers think biodegradable materials like cellulose diacetate (CDA) could replace the traditional forms.
Cellulose Diacetate (CDA) is a plastic-like polymer made from cellulose found in plant walls.
In collaboration with Eastman, WHOI scientists have prepared a new version of CDA, the fastest degrading bioplastic in an ocean environment. In a new study published in ACS Sustainable Chemistry & Engineering, researchers found that adding small foams to the CDA material makes it degrade 15 times faster. This degradation is even quicker than paper.
“We evaluated several prototyped CDA and conventional PS foams for their marine degradation, determined relationships between degradation rate and foam properties, and demonstrated the value of CDA foams as next-generation materials that are material efficient, nonpersistent, and enable circularity,” says the study.
Scientists monitored the CDA and other plastic materials like Styrofoam in a tank of continuously flowing seawater. As the degradation of plastic depends on the interplay of microbial, environmental, and material properties, the continuous flow of seawater enabled dynamics of the microbially active ocean into the lab.
After 36 weeks of compliance, CDA lost 60-70% of its original mass, while the traditional Styrofoam showed almost negligible signs of degradation during the same time frame.
In another study, WHOI experimented with straws made of standard plastic, paper, solid CDA, and foamed CDA. The straws made from solid CDA and paper showed the quickest degradation. Among the CDAs, the foamed CDA lost mass 190% faster than its solid counterparts.
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“As a materials scientist and engineer, it’s been exciting to demonstrate that foams can be materially efficient, meaning they achieve functionality using the least amount of material possible, reducing cost and many environmental impacts,” said James, the author of the study. “In addition, when they are made from biodegradable plastics, they can be one of the least persistent forms of a material.”
As the Styrofoam plastic and single-use plastics used in most takeaway containers are not biodegradable, replacing them with fast-degrading polymer is an urgent call. The authors of the study have highlighted the potential of foamed CDA in addressing the challenges of single-use plastic packaging.
Eastman, a material innovation company, is already using foamed CDA to make compostable, lightweight trays. This initiative serves as an alternative to polystyrene trays.
The study is likely to replace earth-friendly plastic
“The properties of foams make them ideally suited for many packaging and insulation applications, and this research shows that foams made of biodegradable materials will rapidly degrade in the marine environment, should they accidentally end up there. Embracing biodegradable materials for consumer goods is a critical step towards preserving our environment, reducing plastic pollution, and fostering sustainability for future generations,” said the author Carbeck.
Journal Reference
- Bryan D. James, Yanchen Sun, Kali Pate, Rahul Shankar, Mounir Izallalen, Sharmistha Mazumder, Steven T. Perri, Katelyn R. Houston, Brian Edwards, Jos de Wit, Christopher M. Reddy, and Collin P. Ward ACS Sustainable Chemistry & Engineering Article ASAP DOI: 10.1021/acssuschemeng.4c05822
