Location: Bioproducts ResearchTitle: Evaluation of biodegradation of polylactic acid mineral composites in composting conditions
|FLYNN, ALLISON - Former ARS Employee|
|McCaffrey, Zachariah - Zach|
|Glenn, Gregory - Greg|
|Wood, Delilah - De|
|Orts, William - Bill|
Submitted to: Journal of Applied Polymer Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2019
Publication Date: 3/2/2020
Citation: Flynn, A., Torres, L.F., Hart-Cooper, W.M., McCaffrey, Z., Glenn, G.M., Wood, D.F., Orts, W.J. 2020. Evaluation of biodegradation of polylactic acid mineral composites in composting conditions. Journal of Applied Polymer Science. 137(32). Article 48939. https://doi.org/10.1002/app.48939.
Interpretive Summary: Overproduction of plastics is an increasing public concern due to the large amounts of waste plastics amassing in marine environments and accumulating as litter. A large portion of the waste is from single-use items in the form of packaging. Plant-based poly-lactic acid (PLA) is finding its way into single-use items which is a benefit over the use of petrochemical-based plastics. However PLA is difficult to biodegrade thus, even the plant-based plastics accumulate in the environment. The enhancement of the biodegradation rate of PLA filled with commercially available soil amendment product or a nanoclay was studied. The process could increase PLA degradation rate in industrial compost systems and thus decrease plastic accumulation in the environment.
Technical Abstract: In this study, the enhancement of the biodegradation rate of polylactic acid (PLA) filled with commercially available soil amendment product (NTM) or a nanoclay (Cloisite 25A) were evaluated. Cloisite 25A and NTM were incorporated into PLA at 5, 10, 20 (w/w) through melt blending. Transmission electron micrographs revealed particles with a wide range of sizes that were formed by clumping of many smaller particles. The particles showed good dispersion in PLA by scanning electron microscopy. Under standard composting conditions using a standard technique for aerobic biodegradation of plastic materials, it was shown that the addition of NTM enhanced the biodegradation rate of PLA composites by 3- to 4-fold compared to neat PLA. Linear kinetics were used to obtain induction periods, half-lives, and rates of mineralization. Finally, mechanical and thermomechanical properties of these blends were compared with PLA.