Plasma-Activated Water/Ultrasound as a Green Method to Modify Wood Fiber By-Product: Insights of Their Mechanical...

Exploring new ecological and simultaneous processes to modify wood fibers (WF) by-products is a required pathway toward circular economy and sustainability. Thus, plasma-activated water (PAW) and ultrasound (U) were employed as alternative methods to modify WF in a continuous process. Such treatments promoted the etching and cavities on the WF surface that destabilized the hydrogen bonds of the hemicellulose and lignin molecules, increasing the cellulose fraction. The addition of modified WF in the PLA matrix increased the storage modulus (2937 up to 5834) and Young modulus (3990 up to 6000 MPa), indicating well fiber/matrix interactions. The results corroborated that the use of modified WF as fillers could reduce the cost of extruded PLA-based composites and expand the production of bio-based materials for the mobility or packaging field.