Bioplastic That Decomposes in the Ocean Faster Than Paper

Billions of microplastic particles are already littering seas and oceans, posing a threat to marine ecosystems and human health. American scientists, on the hunt for new biodegradable materials to relieve the environment, have developed a bioplastic. It combines high user functionality with an exceptionally rapid rate of decomposition. Its potential applications include food packaging, straws, and disposable cups—items that often end up in the sea.

Foamed bioplastic from cellulose

The breakthrough discovery was made by a team of researchers from the Woods Hole Oceanographic Institution (WHOI) in Massachusetts. After years of experiments, the scientists managed to foam cellulose diacetate (CDA), a polymer derived from wood pulp that has been in use for some time. By increasing the material’s porosity through foaming, they reduced its ocean degradation time by a factor of 15 compared to traditional CDA. This new material even decomposes faster than paper.

The study results were published in the October issue of ACS Sustainable Chemistry & Engineering. Lead author Collin Ward expressed enthusiasm about the potential of the new bioplastic, emphasizing that it meets consumer demands while decomposing in the ocean faster than any other known material. “It’s a major success in a field that often focuses on the negative aspects of plastic pollution rather than looking for solutions to the problem,” Ward added.

The short life of a straw

The WHOI team collaborated with scientists from Eastman, a company that manufactures bioplastic and agreed to provide raw materials for the experiments. In a specially constructed laboratory, a tank with continuously circulated seawater was set up to mimic natural conditions. Traditional solid CDA and its foamed version were placed in the tank. Conditions such as temperature, light exposure, microbial presence, and nutrients, typical of marine environments, were carefully maintained.

After 36 weeks, the foamed CDA lost 65-70% of its original mass. Its degradation rate was 15 times faster than that of classic CDA. For comparison, styrofoam, also a type of foamed polymer, did not lose any of its mass during this period.

In an earlier study, WHOI scientists placed four types of straws in a dynamic tank with seawater: a classic plastic straw, a solid CDA straw, a paper straw, and a foamed CDA straw. The latter degraded at the fastest rate by far. According to current knowledge, no other plastic or bioplastic decomposes in the ocean as quickly as foamed CDA.

From innovation to application

The new bioplastic is likely to be put into practical use soon. Eastman, which participated in the research, is already turning positive results into the production of lightweight food packaging trays to replace commonly used styrofoam trays. The potential applications are, of course, much broader.

Jeff Carbeck, Eastman’s vice president for corporate innovation, emphasized the importance of collaboration between academia and industry to accelerate the search for solutions that will help the world tackle pressing challenges. He believes that CDA foam could revolutionize the single-use packaging and insulation sectors. If it ever ends up in the ocean, it will undergo rapid and safe degradation.

Notably, this new bioplastic was designed to be produced from raw CDA using the same equipment currently used for manufacturing styrofoam packaging. This is yet another clear benefit of collaboration between scientists and manufacturers. It’s worth noting that global styrofoam production today exceeds 15 million metric tons annually, much of which ultimately ends up in landfills and water bodies.

“Developing a new plastic technology that is fossil-fuel-free, compostable, and doesn’t persist as ocean pollution is a win for both consumers and the environment,” said Collin Ward.