Wood Protective Fungicidal Treatment: Quaternary Ammonium Molecules Grafting on Cellulose Assisted by Afterglows at Atmospheric Pressure

Wood or cellulosic materials protection against fungi is possible by binding covalent molecules as quaternary ammonium compounds (QAC) on the hydroxyl reactive groups present in cellulose. This work firstly consists in the synthesis of a specific quaternary ammonium molecule containing a long aliphatic chain and an epoxide reactive group: Glycidyldimethyldodecylammonium chloride (GDDAC). Fungicidal properties of this molecule have been proven. Secondly, afterglows issued from atmospheric pressure Dielectric Barrier Discharges (DBDs), can assist QAC grafting on cellulose. The efficiency of the reaction is improved by adding a few percentage of oxygen in nitrogen DBD. Antifungal efficiency of GDDAC grafting on wood sawdust is finally shown demonstrating the great interest of such process. DBD afterglow treatments in N2 and N2/O2 are used to graft quaternary ammonium compounds (QACs) on cellulose and wood. Glycidyldimethyldodecylammonium (GDDAC) is useful to protect wood against fungi attack and its covalent binding allows avoiding leaching when wood is exposed to rainwater. We show that afterglow treatments are efficient to increase the fixation of QAC on cellulose and that a small amount of GDDAC grafted on wood is efficient to prevent fungi growth.