Potential roles of polyacrylate- silicate sodium compound on weathering performance of a wood polymer composite

The aim of the current research work was to prepare a kind of the wood-polymer composite from fir wood with a combination of sodium silicate and polyacrylate compound and also to study their effects on prohibition in leaching of the sodium silicate and also increase in resistance of wood against the weathering. For this purpose, the test samples were initially prepared according to the standard methods. Afterwards, the specimens were impregnated with the sodium silicate and the polyacrylate under a vacuum of 0.5 bar for 30 minutes and then a pressure of 6 bar for 3 hours in a cylinder. The samples were then exposed to the natural weathering for 80 days period to study their weathering resistances, changes in color coordinates, roughness and also wettability of the treated wood as well as leaching of the impregnation compounds. The results showed that the presence of the polyacrylate had a higher potential performance to reduce leaching of the sodium silicate from wood. The polyacrylate also reduced the color changes and surface roughness of the samples due to the degradation during the weathering period. It was also revealed that the polyacrylate increased the hydrophobicity of the samples and reduced the wettability of the surface of the samples against the water droplets during the natural weathering. Among those treatments, the treatment S60- Pa50 - (1: 2) indicated the best performances compared to other treatments against the natural weathering and prohibition in leaching of the sodium silicate from the treated wood due to the higher amount of polyacrylate.