Film properties of waterborne paint based on Fraxinus mandshurica substrate

  Objective  Fraxinus mandshurica, as a kind of excellent hard wood, is often used to make medium and high grade furniture. The waterborne paint is a very environmentally friendly paint, and it is of great practical significance to study the coating properties of Fraxinus mandshurica for improving the performance of waterborne paint and optimizing the coating process. In this paper, the film properties and adhesion mechanism of waterborne paint on the surface of Fraxinus mandshurica were systematically studied, which can provide theoretical support and scientific basis for the application and research of waterborne paint on wood.

  Method  In this paper, commercial waterborne paint was used to paint Fraxinus mandshurica and the film properties were measured according to the corresponding standards. SEM and FTIR were used to explore the adhesion mechanism of waterborne paint on the substrate.

  Result  The film thickness of cured waterborne paint on substrate was 96.63 μm, the hardness was H, the adhesion was up to level 0, the water resistance was up to grade 1, the color difference value ΔE before and after coating was 9.86, which could keep the wood color of the substrate. Because the priming paint evenly covered the surface of the substrate, sealed the hydrophilic hydroxyl in the substrate, and improved the hydrophobic property of the substrate surface, the contact angle of the substrate surface increased by about 10°. The surface glossiness of the coated substrate was significantly improved, and the glossiness in parallel texture direction was 40.4% higher than that in the vertical direction. This is mainly due to the fact that most of the cells making up the wood are arranged in an axial direction, and the waterborne paint is mainly filled in the large cell cavities arranged longitudinally, but it is difficult to penetrate into the cell walls with nano level pores. The combination of waterborne paint and substrate was mainly in the physical form of mechanical interlocking, and chemical reactions also occurred. The increase of the intensity of the peak of1 148 cm^{− 1} indicated that the carboxyl group in the waterborne paint had esterified with the hydroxyl group in the substrate; the appearance of the peak 1 063 cm^{− 1} showed that the cellulose in the substrate had etherified with the hydroxyl group in the waterborne primer.

  Conclusion  The waterborne paint has good adhesion on the surface of Fraxinus mandshurica, has a good protective performance and can effectively improve the visual effect of the substrate, so as to improve its commercial value.