Solvent-free microwave-assisted synthesis and characterization of polybenzoxazine as a thermochromic material for smart coatings

Effect of Coating Process on Performance of Reversible Thermochromic Waterborne Coatings for Chinese Fir

The effect of the coating process on the properties of reversible thermochromic waterborne coating on the surface of Chinese fir was examined. The results demonstrated that the most critical process parameter affecting the color difference and gloss of the coating was the way of adding thermochromic ink. The coating process had little influence on the adhesion, impact resistance adding, liquid resistance, and original properties of the coating. There was no obvious gloss variation in the coating under different coating processes. For the (3+3) layered coatings, when the thermochromic ink was added to the topcoats, the discoloration performance was the most obvious and the comprehensive performance of coating was better. Meanwhile, the gloss was 55.6%, the adhesion grade was grade 0, the impact resistance was 5.0 kg·cm, the liquid resistance grade of the coating to sodium chloride, ethanol and detergent was grade 1, and the liquid resistance grade to red ink was grade 3. The discoloration performance of the coating was stable under the conditions of aging and time change. This study provides new insight into preparing thermochromic intelligent waterborne wood coatings with potential practical applications on Chinese fir wood surfaces, and also lays a foundation for its application in furniture engineering.

The Effect of Glass Fiber Powder on the Properties of Waterborne Coatings with Thermochromic Ink on a Chinese Fir Surface

In this study, the effect of glass fiber powder on the properties of waterborne coatings with thermochromic ink was investigated, using Chinese fir board as the base material and temperature-sensitive thermochromic waterborne coatings with thermochromic ink as the paint base. The concentration of glass fiber powder was determined when the microstructure, optical properties, mechanical properties, liquid resistance, and heat preservation effect were the best. The results showed that the paint film with glass fiber powder concentration of 1.0% to 7.0% had better discoloration performance. With an increase of the glass fiber powder concentration, the gloss of the paint film decreased gradually, and when the concentration of glass fiber powder was 0% to 5.0%, the gloss of the paint film was better. The concentration of glass fiber powder had no effect on the adhesion, impact resistance, and liquid resistance. In the first 2.5 min, the temperature value of the waterborne coating with 3.0% glass fiber powder was higher than that without glass fiber powder, which has a certain heat preservation effect. When the glass fiber powder content was 3.0%, the microstructure of paint film was the best. The composition of paint film with different glass fiber powder concentrations was not different and the discoloration performance of paint film with heat preservation effect was not affected by time. The analysis showed that the waterborne coating with 3.0% glass fiber powder had the best comprehensive performance. This work provides a technical reference for the industrialization of heat preservation and thermochromic coating on wood.