Compostability and Ecotoxicity of Poly(lactic acid) and Starch Blends

This paper revealed the compostability of poly(lactic acid) (PLA) and PLA/starch blends with various amounts of starch contents. The results showed that the ultimate aerobic biodegradation under controlled composting conditions of PLA and PLA/starch with 30, 50 and 70 wt% starch contents were 83.43%, 84.28%, 88.04% and 95.83%, respectively. Under the same testing conditions, the biodegradation of cellulose, as a positive material, was 84.89%. In the disintegration testing, the tested materials were completely biodegraded and no residuals were observed through visual inspection after 30 days. In ecotoxicity test, the rate of germination and plant growth of monocotyledon and dicotyledon on the resulting compost were no significant different when compared to blank compost under. It can be concluded that the PLA and PLA/starch blends were clearly safe for the ecosystem. Furthermore, these materials were biodegradable and compostable materials as they pass all requirements of ISO 17088.