Effects of Thermochromic Fluorane Microcapsules and Self-Repairing Waterborne Acrylic Microcapsules on the Properties of Water-Based Coatings on Basswood Surface.

The effect of the addition of fluorane microcapsules and urea formaldehyde resin (UF) waterborne acrylic resin microcapsules on the comprehensive properties of the water film on the surface of basswood was studied. Three-factor and two-level orthogonal experiments were carried out with "fluorane microcapsule content", "aqueous acrylic resin microcapsule content" and the "fluorane microcapsule addition method" to prepare a self-repairing thermochromic coating. The optical, mechanical, microstructure and self-repairing properties of the film were optimized by independent experiments on the maximum influence factors of the fluorane microcapsule content. It was concluded that the topcoat with 15% fluorane microcapsules and primer added with 15% water acrylic resin microcapsules had better comprehensive properties. The temperature range was 30-32 °C, the color difference at 32 °C was 72.6 ± 2.0, the 60° gloss was 3.3%, the adhesion was 0 grade, the hardness was 4 H, the impact resistance was 15.0 ± 0.8 kg∙cm, the elongation at break was 17.2% and the gap width was reduced by 3.5 ± 0.1 μm after the film was repaired. The repair rate reached 62.5%. By using microcapsule embedding technology, the repair agent and discoloration agent are embedded in the matrix. The waterborne acrylic resin microcapsules can effectively inhibit crack formation in the coating, and the fluorane microcapsules can achieve the thermochromic property of the coating. This study provides a new research idea for the self-repairing thermochromic dual function of a water-based coating.