Effect of Microcapsules with Different Core–Wall Ratios on Properties of Waterborne Primer Coating for European Linden

Effects of Adding Methods of Fluorane Microcapsules and Shellac Resin Microcapsules on the Preparation and Properties of Bifunctional Waterborne Coatings for Basswood

In this paper, urea-formaldehyde resin microcapsules with shellac resin as core material were prepared by in-situ polymerization. Morphologies of shellac resin microcapsules were characterized by optical microscope (OM) and scanning electron microscope (SEM). Both microcapsules were spherical in shape. The encapsulation property of shellac resin was proved by Fourier transform infrared (FTIR). Shellac resin microcapsules and fluorane microcapsules were added to waterborne primer or topcoat at the same time to prepare waterborne coatings with thermochromic and self-healing dual functions. The effects of microcapsules on optical properties, mechanical properties, self-healing properties, anti-aging performance, and thermoreversible discolouration mechanism of coating films were studied. These results showed that the topcoat with 10.0% fluorane microcapsules and 5.0% shellac resin microcapsules had a better comprehensive performance. At this time, the colour of coating transformed yellow into colourless at 32 °C, and it had a good colour recovery. Shellac resin microcapsules endowed the coating with self-healing performance, and the self-healing rate was 35.9%. The research results provide a reference for the progression of multifunctional wood coatings.

Mechanism of Thermochromic and Self-Repairing of Waterborne Wood Coatings by Synergistic Action of Waterborne Acrylic Microcapsules and Fluorane Microcapsules

The fluorane thermochromic microcapsules and waterborne acrylic resin microcapsules were added into waterborne coatings at the same time to prepare intelligent waterborne coating film with dual functions of color change and self-repairing. The coating film prepared by adding 15.0% fluorane microcapsules and 5.0% waterborne acrylic resin microcapsules to the primer at the same time had better comprehensive properties. At this time, the coating film changed from yellow to colorless. The repair rate of the coating film was 58.4%. When the temperature was lower than 32 °C, waterborne acrylic resin microcapsules can improve the thermochromic performance of the coating film with fluorane microcapsules. Waterborne acrylic resin microcapsules can alleviate the color change of coating film with fluorane microcapsules. The fluorane microcapsules can improve the self-repairing performance of coating film with waterborne acrylic resin microcapsules. The results lay a theoretical and technical foundation for multifunctional coating film.

Preparation of Silver Antibacterial Agents with Different Forms and Their Effects on the Properties of Water-Based Primer on Tilia europaea Surface

Micron silver particles prepared by the chemical reduction method, urea formaldehyde resin-coated nano-silver solution microcapsules, and nano-silver solution were used as three kinds of antibacterial agents. These were added to a water-based primer on the surface of Tilia europaea in contents of 1.0%, 4.0%, 7.0%, 10.0%, 13.0%, and 16.0%. In order to achieve the best comprehensive performance of the water-based primer, the mechanical, optical, and antibacterial properties of the three antibacterial coatings with different contents of silver antibacterial agents were explored. It was concluded that when the antibacterial agent content was 4.0%, the color difference, impact resistance, adhesion, and gloss of water-based primer on the Tilia europaea surface were better. When the antibacterial agent content added was 16.0%, the antibacterial properties of the three groups of coatings improved to 94.89%, 81.75%, and 83.98%, respectively. The results provide a research idea for the preparation of antibacterial coatings on the surface of wood furniture.

Effect of Microcapsule Concentration with Different Core-Shell Ratios on Waterborne Topcoat Film Properties for Tilia europaea

The effects of the core-shell ratio and concentration of urea formaldehyde (UF) resin-coated waterborne acrylic resin microcapsules on the optical properties, mechanical properties and liquid resistance of waterborne topcoat coatings on the surface of Tilia europaea were investigated. With the increase of microcapsule concentration, the color difference and hardness of the paint film gradually increased, the gloss and adhesion of the paint film gradually decreased, and the impact resistance and elongation at break of the paint film increased first and then decreased. With the increase of the core-shell ratio, the hardness and impact resistance of the paint film increased first and then decreased, and the adhesion of the paint film decreased gradually. Red ink had a great influence on the liquid resistance of paint film. When the core-shell ratio of UF-coated waterborne acrylic resin microcapsule was 0.58:1 and the microcapsule concentration was 10.0%, the comprehensive performance of paint film on Tilia europaea was better. The prepared self-healing microcapsules applied to the waterborne coatings committed to prolonging the service life of the paint film.

Preparation of Shellac Resin Microcapsules Coated with Urea Formaldehyde Resin and Properties of Waterborne Paint Films for Tilia amurensis Rupr

A two-step in situ polymerization method was utilized to fabricate urea formaldehyde (UF) resin-coated shellac resin microcapsules. The morphology and composition of microcapsules with different core-wall ratios were analyzed by scanning electron microscope (SEM) and infrared (IR) spectrum. The effects of different concentrations of microcapsules on gloss, color difference, hardness, adhesion, and impact resistance of waterborne paint films were studied. At the same time, the self-healing effect of the prepared microcapsules applied to waterborne paint film was discussed. The results revealed that the shellac resin microcapsules coated with UF resin were successfully prepared. At the 0.67:1 and 0.75:1 core-wall ratios, the color differences of the paint film with 0–20.0% (weight percent) microcapsules were small and the color was uniform. Under the condition of 60° incident angle and the same microcapsule concentration, a good gloss was obtained. When the concentration was 20.0%, the hardness of paint film reached the maximum value. The adhesion of paint film was better, which was not affected by microcapsule concentration. When the concentration was 5.0% and 10.0%, the microstructure of paint film was good. The paint film with a 10.0% concentration of the shellac resin microcapsules coated with UF resin had better self-healing performance and the comprehensive performance was better. This paper provides the basis for the industrial application of self-healing waterborne wood paint films.

Effect of Sanding Processes on the Surface Properties of Modified Poplar Coated by Primer Compared with Mahogany

The surface roughness, static and dynamic liquid wettability of modified poplar wood were measured by different surface treatment of brushing primer and sanding. With the increase of the number of grinding paper, the depth parameters Ra, Ry, Rz and Rp of surface roughness of modified poplar decreased, and the density parameter Sm (the average spacing of micro unevenness of contour) decreased at first and then increased. With the increase of number of the grinding paper, the contact angle of water and glycerol for modified poplar wood decreased at first and then increased. After the modified poplar wood was brushed with the primer and sanded with 240# sandpaper, the density parameter Sm was 0.307, the equilibrium contact angle of distilled water was 34.88, and the equilibrium contact angle of glycerin was 36.46, all of which were the lowest number. At this time, the surface roughness was improved, and the modified poplar has the good wettability that is greater than the mahogany wood wettability. Compared with mahogany, the rough depth parameters of the modified poplar are smaller to those of mahogany, but the Sm of modified poplar wood is greater than that of the mahogany. After the same surface pretreatment, the wetting speed of glycerol on the surface of mahogany is higher than that of the modified poplar.