Performance of composite materials by wood fiber/polydopamine/silver modified PLA and the antibacterial property

Inspired by marine mussels, dopamine with a catechol structure was self-polymerized in a weak alkaline environment and deposited on the surface of wood fiber (WF) to enhance the interface between WF and polylactic acid (PLA). At the same time, silver nanoparticles (Ag NPs) were attached to the surface of WF under the reducibility of polydopamine (PDA), giving the composite antibacterial activity against Aspergillus niger. The results showed that PDA and Ag NPs were successfully generated and attached to the WF surface. The thermal stability of WF was improved after the modification, which the maximum decomposition rate temperature of WF/PDA/Ag was increased by 29.2 °C compared with WF. According to relevant analysis, the tensile properties of WF/PDA-PLA were significantly improved. Compared with PLA, the tensile strength and Young's modulus of WF/PDA-PLA were increased by 8.13% and 52.89%. The bacteriostatic circle method measurement showed WF/PDA/Ag-PLA had a particular antibacterial ability for Aspergillus niger.