Synergistic effects of wood fiber and polylactic acid during co-pyrolysis using TG-FTIR-MS and Py-GC/MS

In this study, WF (wood fiber)/PLA (polylactic acid) composites were pyrolyzed to study the synergistic effects during co-pyrolysis of WF-PLA blends. The co-pyrolysis kinetics, mechanism of synergistic effects and products distribution were studied by TG-FTIR-MS and Py-GC/MS. Through the analysis of co-pyrolysis kinetics, it was found that the activation energy of WF-PLA blends was lower than that of sole WF or PLA. The pyrolysis activation energy of 30%wt WF/PLA composites decreased by 70 KJ/mol compared to sole PLA. TG-FTIR-MS and Py-GC/MS analysis showed the production of lactide increased significantly accompanied by a decrease in acetaldehyde and CO during co-pyrolysis. The interactions between WF and PLA promoted the positive synergistic effects. The synergistic effects essentially promoted the free radical reaction of the PLA during copyrolysis, thereby reducing the activation energy of the co-pyrolysis and obtaining more recoverable lactide. This work provided a reference for the reuse of waste PLA and WF in energy field, and provided a solution to the potential PLA pollution.