Investigation of bioplastic degradation for military in-field applications : implementation of sustainable practices into the US military for rapid biodegrading polylactic acid (PLA) plastic in compostable environments

The Army Climate Strategy has identified goals to reduce greenhouse gas (GHG) emissions to reach net-zero Army GHG emissions by 2050. Producing fossil-fuel-based plastics releases GHG emissions and plastic bottles are difficult to dispose, especially in contingency locations. Soldiers prefer hydrating with plastic water bottles, which leads to GHG emissions. This project investigates using bioplastics for water bottles. These bioplastics are produced from natural materials and can break down faster with alternative disposal methods, such as composting. Challenges include finding a material with a stable shelf life and the capability to hold water, but also one that that degrades with ease in the right composting environment. As part of this project, partners at the University of Minnesota are developing a new polylactic acid (PLA) material to fit the material properties needed for this application. Their research is ongoing. Construction Engineering Research Laboratory (CERL) researchers test-ed commercial PLA in calorimeter and incubator studies and with a full-scale demonstration of the commercial composting Sustainable Generation Mobile System. The PLA did not completely degrade, and testing showed mixed results on finished compost quality. Recommendations include continued testing, experimenting with other bioplastics, and changing compost feedstock variables.