A team of researchers from MIT, led by Professor Bradley D. Olsen, has made significant progress in addressing the environmental challenges posed by polymers through the development of a comprehensive biodegradation data set. The team's findings were recently published in the Proceedings of the National Academy of Sciences (PNAS). The research aims to expand the range of polymers that can be tested for biodegradability, as current testing methods are time-consuming and resource-intensive.
Polymers, such as those used in plastic bags, clothing, cookware, and electronics, provide convenience and support our modern standard of living. However, their long-term persistence in the environment presents a significant challenge. The development of biodegradable polymers is crucial for transitioning towards a more sustainable and environmentally friendly economy, as well as addressing the global climate change crisis.
The MIT team, including Ph.D. candidates Katharina A. Fransen and Sarah H. M. Av-Ron, postdoc Dylan J. Walsh, and undergraduate students Tess R. Buchanan, Dechen T. Rota, and Lana Van Note, aims to overcome the limitations of current biodegradation testing methods. By expanding the available data set, they seek to enable the evaluation of a wider range of polymers for their biodegradability.
Professor Olsen emphasizes that while polymer waste significantly contributes to the climate crisis, the study of polymer biodegradation has been confined to a small number of materials due to the time and resource-intensive nature of testing methods. This limited scope hampers the development of new, sustainable materials. The MIT team's work aims to broaden the scope of materials that can be studied for their biodegradability, allowing for increased innovation in materials design and development.
By providing a more extensive biodegradation data set, this research has the potential to accelerate progress towards a green economy and address the challenges posed by non-degradable polymers. The findings of the MIT team contribute to the ongoing efforts in mitigating the environmental impact of polymers and advancing sustainable material solutions.
Unique high-throughput approach
MIT researchers, led by Professor Bradley D. Olsen, have developed a comprehensive biodegradation data set that includes over 600 distinct polyester chemistries. This achievement has been made possible by employing high-throughput synthesis methods, which enable rapid screening of large sample quantities to identify desired properties or functions. The team utilized a clear-zone assay, a method that detects polymer biofragmentation and identifies polymer-degrading bacteria.
The generated biodegradation data set allows for the establishment of structure-property relationships, a fundamental concept in materials science and engineering. By analyzing the chemical details of the polymers and their corresponding properties, the researchers can construct a predictive model for biodegradation. Notably, they explored both linear and nonlinear relationships between structure and biodegradability.
According to Sarah H. M. Av-Ron, one of the Ph.D. candidates involved in the project, the breakthrough lies in the creation of this extensive data set and the subsequent development of qualitative relationships and predictive models. Integrating the complex chemical representation of polymers with machine-learning models proved to be a captivating challenge. The validation accuracy of one representation/model combination reached an impressive 82%, demonstrating the potential of the approach. With additional data, the accuracy of predictions could be further improved.
The team's research primarily focuses on polyesters as they offer a significant opportunity for addressing the sustainability crisis associated with polymers and reducing the environmental impact of the polymer life cycle. By expanding the understanding of biodegradable polyesters, the researchers aim to contribute to mitigating the environmental challenges posed by non-degradable polymers.
One strain of bacteria, many chemistries
The biodegradation test generated by this data is both cost-effective and accessible to implement, receiving positive feedback from the industry. Compared to other standards in this field, the data sets are highly reproducible, adding to their value.
Av-Ron highlights the uniqueness of their approach, emphasizing that their method employs a single strain of bacteria for testing, providing precise insights into the materials being examined.
Fransen explains that their team takes a different approach from traditional polymer development. Instead of prioritizing material strength first and then assessing biodegradability later, they focus on developing the biodegradability screen upfront. This enables them to efficiently evaluate numerous material options and streamline their research process.
Fransen concludes by acknowledging the growing momentum in sustainable polymer development. She believes that a quick, tangible, and cost-effective solution like theirs could greatly benefit the sustainable materials community.
Fransen's work earned her a J-WAFS Fellowship in 2022, and her collaboration with Av-Ron secured them second place in the 2022 J-WAFS World Food Day Student Video Competition. This research holds promise for creating more environmentally friendly food packaging.
Source: Massachusetts Institute of Technology