木材之化學改質及其膠合性之研究（IV）──不同乙醯化處理材之膠合性及塗裝性

Chemically Modified Wood and Its Gluing Properties (IV)－Gluing and Coating Properties of Acetylated Wood

本研究以醋酸酐對杉木、紅柳桉及紅櫟木等3種木材行乙醯化化學改質，並以尿素甲醛膠合劑（UF）、間苯二酚甲醛膠合劑（RF）、聚醋酸乙烯乳膠（PVAc）、聚胺基甲酸酯膠合劑（PU）、環氧樹脂膠合劑（Epoxy）等，及硝化纖維素塗料（NC lacquer）、聚胺基甲酸酯塗料（PU）等進行膠合及塗裝，探討乙醯化處理材之膠合性及塗裝性。由結果得知UF、RF、PU、Epoxy等膠合劑對乙醯化處理後木材之接觸角減小，乙醯化處理材膠合時以RF膠之膠合效果最佳，UF膠最差，各乙醯化試材之膠合強度值均較未處理材降低。木材經乙醯化處理後之光澤度降低，然經NC lacquer或PU塗料塗裝後之光澤度則乙醯化處理材高於未乙醯化處理者，且其塗膜硬度、耐衝擊性及附著性多優於未經乙醯化處理者。 This Study investigated the gluing and coating properties of acetylated China fir (Cunninghamia lanceolata), red lauan (Shorea spp.) and red oak (Quercus rubra) woods. After the treatment, the treated woods were glued with adhesives such as urea formaldehyde resin (UF), resorcinol formaldehyde resin (RF), polyvinyl acetate emulsion adhesive (PVAc), polyurethane resin (PU) and epoxy resin (epoxy), or coated with coatings such as nitrocellulose lacquer (NC lacquer) and polyurethane coating (PU). The results were summarized as follows: The contact angles of wood with UF, RF, PU and PV Ac were diminished after the wood had been acetylated. Acetylated wood that glued with RF exhibited the best gluing properties, and glued with UF was the worst, but the bonding strength of all acetylated woods was lower than that of untreated woods. Aee1yla1ion uca1mem would reduce the gloss of wood. After the wood specimens were coated with NC lacquer or PU coating, the gloss of acetylated wood was higher than that of untreated wood, and the hardness, impact resistance and crosscut adhesion of the coaling film of acetylated woods were better than that or untreated wood.

This Study investigated the gluing and coating properties of acetylated China fir (Cunninghamia lanceolata), red lauan (Shorea spp.) and red oak (Quercus rubra) woods. After the treatment, the treated woods were glued with adhesives such as urea formaldehyde resin (UF), resorcinol formaldehyde resin (RF), polyvinyl acetate emulsion adhesive (PVAc), polyurethane resin (PU) and epoxy resin (epoxy), or coated with coatings such as nitrocellulose lacquer (NC lacquer) and polyurethane coating (PU). The results were summarized as follows: The contact angles of wood with UF, RF, PU and PV Ac were diminished after the wood had been acetylated. Acetylated wood that glued with RF exhibited the best gluing properties, and glued with UF was the worst, but the bonding strength of all acetylated woods was lower than that of untreated woods. Aee1yla1ion uca1mem would reduce the gloss of wood. After the wood specimens were coated with NC lacquer or PU coating, the gloss of acetylated wood was higher than that of untreated wood, and the hardness, impact resistance and crosscut adhesion of the coaling film of acetylated woods were better than that or untreated wood.