Thermochromic microcapsules were prepared with a thermochromic compound as core material and urea formaldehyde as wall material. The molar ratio of urea and formaldehyde, the mass ratio of core material to wall material, the concentration of emulsifier, and rotating speed were selected to make a four-level and three-factor L₉(3⁴) orthogonal test. It was found that the molar ratio of urea and formaldehyde had the greatest influence on the coating rate of microcapsules. The effects of molar ratio of urea and formaldehyde on the discoloration temperature and coating rate of microcapsules were studied. When the molar ratio of urea to formaldehyde was 1:1.6, the core material: wall material ratio was 4:7, the concentration of emulsifier was 5.0%, and the rotating speed was 1600 rpm, the performance of the microcapsules was the best. When the microcapsule content was 20.0%, the color difference of the paint film was the largest, the gloss and hardness of the paint film decreased with increasing microcapsule content, and the impact resistance of the paint film first increased and then decreased with increasing microcapsule content. The adhesion of the paint film remained unchanged, and was grade 1. When the microcapsule content was 20.0%, the performance of the paint film was at its best. This provides a basis for the application of thermochromic coatings.

Urea formaldehyde @ epoxy resin microcapsules were prepared by two steps in situ polymerization, and the morphology and composition of microcapsules with different mass ratios of core to wall material were examined by scanning electron microscopy (SEM) and infrared (IR) spectroscopy. The microcapsules were added to the waterborne wood coatings to explore the effect of microcapsules on the properties of coatings and their self-repairing characteristics, and the gloss, hardness, adhesion, and impact resistance of the waterborne wood coatings were investigated. The results showed that when the concentration of microcapsule was 10.0% and the mass ratio of core to wall material was 0.83:1, the waterborne wood coatings had a good comprehensive performance and less negative impact. In the scratch test, the waterborne wood coatings with a concentration of 10.0% microcapsule had good repair ability. The possibility of applying the self-repairing technology of microcapsule to waterborne wood coatings was discussed through the preparation and performance characterization of self-repairing coatings and the results can become a guideline for the engineering application of waterborne wood coatings.

An aluminum/waterborne acrylic coating was developed by orthogonal experiments, and the gloss, emissivity, chromatic distortion, hardness, adhesion, impact resistance, and corrosion resistance of the coatings were examined. The results showed that the effect of drying time on the infrared emissivity of coatings was more significant than that of the Al powder concentration and nano-silica slurry. When the drying time was prolonged from 0.5 to 6.0 min, the gloss of the coating decreased slowly and the gloss remained low. The infrared emissivity first decreased and then increased. The infrared emissivity of coatings dried for 2.0 min was better. The L’ value gradually decreased and showed a small change of range. With the increasing of the drying time, the hardness of the coating gradually decreased and was the highest at 0.5–2.0 min. The drying time had no effect on the adhesion level. The impact resistance of the coating was better during the drying period of 1.0–3.0 min. The corrosion resistance of the coating was better at 2.0 min. When the drying time was 2.0 min, the waterborne coating showed the better comprehensive performance. This study provides new prospects in using low infrared emissive coatings for infrared stealth and compatibility with visible light.

Wood surface treatment aims to improve or reduce the surface activity of wood by physical treatment, chemical treatment, biological activation treatment or other methods to achieve the purpose of surface modification. After wood surface modification, the paint film adhesion performance, gluing performance, surface wettability, surface free energy and surface visual properties would be affected. This article aims to explore the effects of different modification methods on the adhesion of wood coating films. Modification of the wood surface significantly improves the adhesion properties of the paint film, thereby extending the service life of the coating. Research showed that physical external force modification improved the hydrophilicity and wettability of wood by changing its surface structure and texture, thus enhancing the adhesion of the coating. Additionally, high-temperature heat treatment modification reduced the risk of coating cracking and peeling by eliminating stress and moisture within the wood. Chemical impregnation modification utilized the different properties of organic and inorganic substances to improve the stability and durability of wood. Organic impregnation effectively filled the wood cell wall and increased its density, while inorganic impregnation enhanced the adhesion of the coating by forming stable chemical bonds. Composite modification methods combined the advantages of the above technologies and significantly improved the comprehensive properties of wood through multiple modification treatments, showing superior adhesion and durability. Comprehensive analysis indicated that selecting the appropriate modification method was key for different wood types and application environments.

The modification experiment of waterborne coating was carried out by adding microcapsules. The wall material of the microcapsule was urea-formaldehyde resin and the core material of the microcapsule was epoxy resin. Core material can improve the toughness of the coating and prevent the cracking of the coating. The influences of different contents of microcapsules and the order of adding microcapsules in the coating process on the properties of gloss, color difference and toughness were studied. The results showed that the gloss of the waterborne coating decreased with the increase of microcapsule content. The color difference of coating increased first and then decreased, and when the microcapsule content was 8.0%, the color difference was the largest. The toughness of the coatings also increased first and then decreased. When the content of the microcapsule was 10.0%, the toughness of the coating was significantly enhanced. When the microcapsules with a content of 10.0% were added to the waterborne coating, under the same process, the coating gloss of microcapsules added to the primer was relatively high, and the coating gloss was the highest when the coating process was three-layer primer and two-layer topcoat. The microcapsule had little effect on the color difference of coating in different coating processes. When the coating process was three-layer primer and three-layer topcoat, the coating toughness was the best when microcapsules were added to the topcoats. This study provides a basis for industrial application of waterborne coatings to enhance their toughness.

Wood surface decoration and protection has become a topic of public concern. In this paper, a temperature-sensitive and reversible thermochromic waterborne wood coating was prepared by using Chinese fir board as the base material and a waterborne wood coating with the pigment slurry of thermochromic microcapsules as the paint base. The optical properties, mechanical properties and chemical resistance of the waterborne wood coating were tested, and its microstructure was analyzed. The results showed that when the concentration of thermochromic pigment slurry was 30.0%, the thermochromic property of the waterborne wood coating was best. The gloss of the waterborne wood coating with 15.0% pigment slurry of thermochromic microcapsules was high. The concentration of thermochromic pigment slurry had no effect on the adhesion, impact resistance, or chemical resistance of the waterborne wood coating. Based on the above results, the waterborne wood coating on Chinese fir had the best comprehensive performance when the concentration of thermochromic pigment slurry was 15.0%. This work will provide a technical reference for the industrialization of the thermochromic coating film on wood.