Effect of various compounding methods on acid red 18050- melamine modified urea formaldehyde resin compound as wood modifier

In order to simultaneously improve the strength and decoration properties of plantation wood, a multi-effect modifier was prepared by compounding acid red 18050(G) with melamine-modified urea formaldehyde resin (MUF). Various compounding methods for MUF synthesis such as adding dye with the first part urea (U1G) or with the second part urea (U2G), or direct blending with MUF resin (BG) were tested. Chinese fir plantation wood was impregnated with these modifiers separately, and its color, color fastness, and dyeing mechanism were studied. The results showed that G had good compatibility with MUF and could prolong its storage time, and all compound modifiers exhibited permeability and coloring effect on Chinese fir wood. Compared with G-dyed wood under the same conditions, all the compound dyed wood had better color fastness to water, and the U2G-dyed was the best, the color fastness to xenon light of U2G dyed wood was greatly improved.. Fourier transform infra-red (FTIR) analysis showed that compared with MUF-modified wood, the dye affected MUF hydroxyl-methylation reaction in U1G, lowered the polycondensation degree, and extended its storage time. The dye might have promoted the ionic reaction between resin amino and dye sulfonic groups in U2G, thus displaying better color fastness.