According to the United Nations Environment Report, plastics account for 85% of all marine waste, and are expected to amass to 23-27 million metric tons by 2040. Since current plastic recovery rates are around 10% or less, projected recovery rates are limited to no more than 80%, and plastic production continues on an exponential growth trajectory, developing new more environmentally compatible materials is essential to limit the impact of fugitive plastic release. Accordingly, there is a need to gain mechanistic insight into environmental processes that govern plastic degradation in order to inform novel material design principles. With this in mind, we developed a series of abiotic (i.e., photodegradation and hydrolysis) and biotic (i.e. biodegradation and mineralization) degradation tests and applied them to a suite of 16 different polymers. The polymers included ten lab-produced polyesters and six other commercially available polymers. The obtained results show that mineralization alone (ISO 23977-1 2020, ASTM 6691-17 2017) underestimates polymer degradation up to five-fold over 28 days (2 to 20% for biodegradation only in contrast to 25 to 30% when abiotic processing is considered). The higher environmental degradation rates varied as a function of polymer composition, and this provides valuable information that can aid the development of design rules for environmentally compatible polymers. Finally, the results imply that more representative environmental weathering rates could be derived from materials testing modified to include both biotic and abiotic pathways. Using this approach to curate large datasets for various polymeric building blocks of interest may one day enable machine-learning driven synthetic chemistry to promote the design of novel materials that meet objective sustainability metrics.

Importance of considering biotic and abiotic natural degradation processes in polymer degradation tests

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.