Biodegradation

The US Navy utilizes PVC balloons, known as Killer Tomatoes, that are inflated onboard then deployed into the ocean to calibrate weaponry. The Navy has requested the investigation of biodegradable polymers to replace the PVC to reduce ocean waste. Two proprietary polymers were obtained from Green Dot Bioplastics, BD3001 and BD3003. The polymers were extruded into sheets, cut to size, and placed into twenty-gallon tanks of circulating marine-water that was obtained from the Cal Poly Pier. The 36 samples were left in their respective tank for up to 53 days. Samples were routinely removed for testing to measure the rate of biodegradability. Biodegradability was tested via DSC, FTIR, SEM, and gravimetry. Both BD3001 and BD3003 performed similarly throughout the biodegradability testing, as neither polymer showed definitive signs that biodegradation occurred during the testing period. These results suggest that they would not eliminate the waste generated from current Killer Tomatoes. The performance was tested via radio frequency welding and tensile testing. Both polymers were able to be welded but exhibited inadequate mechanical properties that were not comparable to PVC. Therefore, both could be manufactured in the same manner as the PVC but may fail to perform the application required by the Navy. It is recommended that the Navy consider longer term in situ testing of prototypes for a more realistic evaluation of biodegradation and performance.