Is Biodegradability a Solution to Plastics Waste Management? – Understanding the Science
Presented by Ramani Narayan (Michigan State University)
A University of Plymouth MAterials and STructures (MAST) research group seminar
Wednesday 04 November 2020 at 14:00-15:30 GMT
Watch the recording of the seminar (80 minutes)
Plastic wastes on land and in oceans have become major societal
issues. Articles in print, television, and social media continue to report on
plastics pollution especially as it relates to findings of microplastics and
fibres in the oceans. Designing thermoplastic polymers to be completely
“biodegradable” in disposal systems like composting and soil (agriculture) in a
specific time and rate can be a viable and responsible “end-of-life” solution,
and contribute to circularity and sustainability. However, much confusion,
misperception, and outright misleading claims abound in the marketplace about
biodegradability and biodegradable plastics.
In this seminar, we review the science of biodegradation and discuss the value proposition for biodegradable and compostable plastics. The concept of polymer materials that degrade and disappear without leaving behind fragments or harmful products is appealing, and literature caries countless papers on the subject. However, many of the products and reports do not demonstrate complete removal from the selected disposal environment by microbial metabolism in a defined rate and time. This @EnvSciTech viewpoint summarises necessary requirements for assessing and reporting plastic biodegradation as solution for plastic waste https://pubs.acs.org/doi/10.1021/acs.est.9b04513. The relationship between polymer structure and the receiving biological environment to biodegradability will be discussed.
Biobased plastics in which fossil carbon of the polymer molecule is replaced in part or completely by renewable bio carbon offers the value proposition of a reduced carbon footprint, enhanced rural agrarian economies, and food security. However, a biobased product is not necessarily biodegradable or compostable.