From wood waste to wood protection: New application of black bio renewable water-based dispersions as pigment for bio-based wood paint

This study aims to assess the effect of two different amounts of bio a renewable black pigment derived from wood waste on the durability of a bio-based wood paint. The effect of this eco-friendly pigment on the aesthetical features of the coatings was evaluated by colorimetric measurements and optical microscopy observations. The durability of the paints was assessed by exposing the samples to UV-B radiation and continuous thermal shocks, analyzing the influence of the presence of the pigment on the protective behavior of the paint by means of infrared spectroscopy analysis, colorimetric inspections, adhesion tests and scanning electron microscope observations. Furthermore, the coatings' durability was confirmed following tests of chemical resistance to liquids, where the pigment did not negatively influence the barrier performance of the polymeric matrix of the paint. Finally, the thermal test evidenced the behavior of the black pigment in increasing the heat absorption by the paint, which suggests its use in structural energy saving applications. Ultimately, this work demonstrates how this bio renewable water-based dispersion, derived by wood waste, can be applied as functional pigment in bio-based wood paint, capable of modifying the appearance of the coating without negatively affecting its protective performance.