Degradability comparison of poly(butylene adipate terephthalate) and its composites filled with starch and calcium carbonate in different aquatic environments

We investigated the degradation behavior of biodegradable poly(butylene adipate terephthalate) (PBAT) and its composites containing starch (PBAT-starch) and calcium carbonate (PBAT-CaCO3). The test splines were immersed in six different water bodies with various microbial compositions and salt concentrations for a 56 week period to obtain consistent experimental data. The results show that the pure PBAT degraded very slowly in the six water bodies, with a maximum weight loss of only 4.7% over the 56 week study period. Strips of the PBAT-starch composite showed a significantly accelerated biodegradation in microbe-containing water; the degree of degradation depended largely on the type and abundance of microorganisms in the water bodies. Conversely, compared with the pure PBAT strips, PBAT-CaCO3 showed less degradation in the various water bodies. A comparison of degradability between the strips immersed in sterilized distilled water and sterilized seawater indicated that inorganic salts did not significantly affect the degradation of PBAT. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46916.