Effect of Nano-Silver Solution Microcapsules Mixed with Rosin-Modified Shellac Microcapsules on the Performance of Water-Based Coating on Andoung Wood (Monopetalanthus spp.)

To obtain dual functions of antibacterial and self-healing of a coating, nano-silver solution microcapsules coated with urea formaldehyde resin were selected for antibacterial agents, and rosin-modified shellac microcapsules coated with melamine formaldehyde resin were selected for repairing agents. The optical, mechanical, antibacterial, self-healing, and other physicochemical properties of the coatings were analyzed. The method of adding two microcapsules independently did not affect the coating’s hardness. When the primer was prepared by self-healing microcapsules and the topcoats were prepared by antibacterial microcapsules, the hardness of the prepared coatings was maintained at 3 H, with the adhesion up to class 2, the impact strength up to 18 kg·cm, and the roughness as low as 1.144 µm. The elongation at fracture of the coatings prepared by adding microcapsules independently was improved by 2.2%. The self-healing microcapsules release the repair agents to improve the mechanical properties of the coatings. In terms of the antibacterial properties of the coatings, the method that involves adding the microcapsules independently is better than mixed adding. Against Escherichia coli, the antibacterial rate of coatings prepared by adding microcapsules independently reached 82%. Against Staphylococcus aureus, the antibacterial rate of coatings reached 83.3%. At the same time, the self-healing rate was up to 41.1%. The two microcapsules were added to the water-based coating independently to obtain antibacterial and self-healing functions with good comprehensive properties. By modifying coatings on the Andoung wood (Monopetalanthus spp.) with antibacterial microcapsules and self-healing microcapsules, it is possible to obtain good antibacterial properties, further protect the wood substrate, and broaden the application range of functional coatings.