INVESTIGATION ON BLEACHING APPLICATIONS WITH C2H2O4 AND H2O2 + NaOH CHEMICALS ON IROKO (Milicia excelsa Welw. C.C. Berg) WOOD

In this study, selected surface characteristics (color parameters, glossiness, and whiteness index: WI*) of iroko (Milicia excelsa Welw. C.C. Berg) wood were investigated following bleaching treatments using two different chemicals: oxalic acid (C2H2O4) and hydrogen peroxide + sodium hydroxide (H2O2 + NaOH). The surfaces that underwent bleaching treatment were compared with surfaces that did not undergo bleaching. The obtained results were analyzed using an SPSS program. All tests yielded significant findings in their variance analyses. The application of both bleaching chemicals to wooden surfaces at 60 and 85 degrees led to decreased glossiness levels in both perpendicular and parallel fiber orientations. Furthermore, decreases were noted in the measurements of WI*, a*, C*, and b* values. Furthermore, decreases were noted in the measurements of a*, C*, and b* values. When subjected to the C2H2O4 chemical, the ΔE* values were determined as 2.20, whereas they measured 4.09 under exposure to the H2O2 + NaOH chemical. The Δa*, Δb*, and ΔC* values were identified as negative. The utilization of chemicals led to changes in the surface characteristics of the wooden material.