Improving Surface Properties of Wood Material Against Weathering by Using New Bio-based Epoxy Nanocomposites

The present study investigates the potential of new bio-based epoxide nanocomposite coatings for wood surfaces to replace BPA (bisphenol A)-based commercial wood coatings in terms of their surface properties. This study focuses on the use of environmentally friendly and BPA-free new bio-based epoxy coatings and their nanocomposite derivatives for the wood surface. Both the resin and the curing agents are derived from natural sources. The study is original as it uses sustainable natural resources in the coatings industry and develops costeffective and readily available systems compared to those derived from petroleum. The research is also original as it is the first to use moss oil and turpentine oil as curing agents in epoxy resin curing reactions. These two oils have similar chemical structures, and the results are comparable. In addition, the effect of nanoparticles on the surface properties of bio-based coatings was investigated. In this study, Oriental beech was used as wood. New bio-based epoxide nanocoatings were produced using tung oil-based epoxide resin (ETO) as the coating material. Additionally, hardeners such as moss oil and turpentine oil were also used. The first step in making ETO was to combine tung oil with glycidyl methacrylate. After premixing the epoxide resin with carbon nanoparticles (graphene, CNTs, and fullerenes), moss oil and turpentine oil were used as bio-based hardeners to cure the resin. The produced materials were then applied to the wooden surface as a coating, and after weathering for 3 months, the colour, gloss and surface roughness of the wood were examined. The results showed that after weathering, the ΔL* value of all test samples decreased. According to the results of the total colour change (ΔE*), the samples of epoxidized tung oil with carbon nanotubes (TEC) added gave the lowest value and were the most stable against colour change. According to the gloss test results, all samples lost gloss after weathering. In addition, TEC samples showed the lowest gloss loss. After weathering, roughness parameters of all samples increased. At all three roughness (Ra, Rz and Rq) values, the samples of epoxidized tung oil (TE) showed the least roughness increase and were the most stable against surface roughness.