Assessment of the Degradability of Commercially-Available Biodegradable Plastic Utensils in Soil and UV

摘要

Biodegradable plastics are viewed as one of the most promising solutions to plastic waste dilemma due to its natural degradative properties. Fossil fuel-based polymers have been infused with bio-based additives (e.g. starch) and have been used to produce biodegradable plastic products such as bags and cutleries. While several studies have dealt with degradation of polymers with bio-based additives, there is work yet to be done on degradation of commercially-available biodegradable plastic products. Here we evaluate degradability upon exposure to soil incubation and UV of three common starch-based plastic utensil brands in the Philippines that claim biodegradability. Analysis of IR absorbance spectra of post-exposure samples indicated high propensity towards photodegradation. Furthermore, estimation of full degradation period confirmed the biodegradability of starch-amended plastics which were limited to two brands. The presence of 19.22% and 24.18% starch in the plastic showed complete decomposition period of 156 and 92 days, respectively. This is a significant improvement over poor degradability exhibited by conventional plastics which often takes 450 to 1000 years. The reduction of degradation time through starch incorporation may prove to benefit manufacturers in fabricating more environmentally-friendly plastic products in the future.