Tannin- caprolactam and Tannin- PEG formulations as outdoor wood preservatives: Weathering properties

Key message: This article presents the leaching, fire and weathering resistance improvements of samples treated with tannin-based wood preservatives added of caprolactam. PEG-added formulations show limited applicability. The FT-IR and13C-NMR analyses of the caprolactam-added formulations show some evidences of copolymerization. Context: Tannin-boron wood preservatives are known for their high resistance against leaching, biological attacks, fire as well as for the good mechanical properties that they impart to wood. These properties promoted these formulations for being a candidate for the protection of green buildings. However, the low elasticity of these polymers and their dark colour implied limited weathering resistances. Aims: The aim of the study is to find suitable additives for tannin-based formulations to overcome their limited weathering resistances, without compromising the other properties. Methods: Treatment, leaching and fire tests, dimensional stability as well as artif...