Effect of Tea Tree Essential Oil@Chitosan Microcapsules on Surface Coating Properties of Pine Wood

Pine wood has a natural, rustic, and environmentally friendly style and is used in a large number of applications in the furniture industry. However, its soft and porous texture makes it susceptible to bacteria, mould, and other micro-organisms. Pine wood was selected as the test substrate, and tea tree essential oil@chitosan (TTO@CS) microcapsules with emulsifier concentrations of 4%, 5%, and 6% were added to the waterborne topcoat at a content of 1%–9% (in 2% intervals) to investigate their effect on the surface coating properties of pine wood. With the increase in microcapsule content, there was an overall increase in colour difference and light loss rate of pine wood surface coating, and the reflectance showed an increase and then decrease. The overall performance of the pine wood surface coatings containing 7% of 13# microcapsules was found to be excellent: the antimicrobial activity of the coatings was 62.58% for Escherichia coli and 61.29% for Staphylococcus aureus after 48 h, and the antimicrobial activity of the coatings was 40.14% for Escherichia coli and 38.89% for Staphylococcus aureus after 4 months. The colour difference in the coating was 2.37, and the light loss was 63.71%. The reflectance value was found to be 0.6860, while the hardness was determined to be 2H and the adhesion class was categorised as one. The impact resistance class was determined to be three, while the roughness was measured at 1.320 μm. The waterborne coating on the surface of pine wood was modified by microencapsulation technology with the objective of enhancing the antimicrobial properties of pine wood and expanding its scope of application.