Lifetime estimations of biodegradable polymers under realistic temperatures in the marine environment script; data and results

Temperature holds the key towards evaluating the lifetime of plastic waste and understanding the long-term persistence of plastic in aquatic environments. Natural environmental conditions often provide less optimal temperatures for biodegradation compared to laboratory standard tests. In this study, we measured the CO2 evolution in natural seawater for 63 days on PHBV, PHBH, and cellulose film (biodegradable cellophane) substrates at 10.0 ℃, 20.0 ℃ and 30.0 ℃. The empirical data collected was used to model polymer behavior by applying the reparametrized Arrhenius equation to obtain lifetime estimations at the tested temperatures but also at the average ocean temperature (4.0 ℃). Our empirical data showed similar values to the estimations within the measured temperature and time ranges. Notably, at 4.0 ℃ we found that PHBH has the potential to biodegrade faster than PHBV by reaching 90% biodegradation in 172 days. This study validates the use of the Arrhenius equation approach to polymer behavior modelling for use in the marine environment and offers insights into the biodegradation rates of materials at a range of temperatures consistent with marine environments without the need to perform long-term incubation experiments.