Agricultural and Biosystems Engineering, Chemical and Biological Engineering, Center for Industrial Research and Service (CIRAS)
Journal or Book Title
Journal of Renewable Materials
Research Focus Area(s)
Biological and Process Engineering and Technology
Presented in this study is a novel recycling strategy for poly(lactic acid) (PLA) in which the depolymerization is rapidly promoted by the base–catalyzed hydrol–/alcohol–ysis of the terminal ester bonds under mild conditions. Post–consumer PLA water bottles were cut into approximately 6 × 2 mm plastic chips and heated to 50–60×C in water, ethanol, or methanol as the depolymerization medium. A variety of carbonate salts and alkaline metal oxides were screened as potential catalysts. High–power ultrasound was also investigated as a means to accelerate the PLA decomposition. Both mass loss and HPLC analysis of the treated suspensions showed that the conversion of PLA to lactic acid/lactic esters was achieved with yields over 90% utilizing either ultrasonics or a hot bath. It was found that the most rapid decomposition occurred in solution of sodium hydroxide in methanol at 50oC, in which maximum depolymerization was complete in 5 min. It was also seen that the degree of crystallinity affected the rate of depolymerization.
Scrivener Publishing LLC
Grewell, David A.; Srinivasan, Gowrishankar; and Cochran, Eric W., "Depolymerization of Post-Consumer Polylactic Acid Products" (2014). Agricultural and Biosystems Engineering Publications. 842.