Assessing the Biodegradability of 2‐Methylene‐1,3‐Dioxepane ( <scp>MDO</scp> )‐Based Multicomponent Polymers Under Aerobic Composting Conditions

ABSTRACT The increasing accumulation of plastic waste in the environment has spurred the development of compostable polymers. Butyl acrylate/vinyl acetate (BA/VAc) copolymer formulations incorporating varying amounts of 2‐methylene‐1,3‐dioxepane (MDO) monomer are subjected to a 60‐day composting process, with their biodegradation monitored via CO 2 emissions. The MDO is added to the formulation to provide ester bonds in the polymer backbone to promote their hydrolysis and facilitate the breakdown of the polymer into smaller fragments. A lab‐made composting setup based on the ASTM D5338 standard is used to provide continuous monitoring of environmental conditions and CO 2 emissions to track biodegradation. The highest 60‐day biodegradation observed is 12.49% for a sample containing ~9 mol% MDO. This contrasted with BA/VAc samples without MDO, which have zero biodegradation. Biodegradation is influenced by the amount of ester groups (i.e., ring‐opened MDO content), as well as the polymer gel content. An additional experiment with carboxylated cellulose nanocrystals (cCNCs) in the BA/MDO/VAc formulation is shown to promote even greater biodegradation due to the increased hydrophilicity and improved microbial access provided by the cCNCs. Overall, this study demonstrates that MDO‐based formulations, especially those incorporating cCNCs, show promise as environmentally friendly, compostable products in support of a more sustainable polymer industry.