Bio-based consolidants for waterlogged archaeological wood: Assessment of the performance and optimization of the diagnostic protocol

New bio-based polymers used as consolidants for waterlogged archaeological wood were studied and their performance on real wooden samples was assessed. In particular, three oligoamides (oligo ethylene-l-tartaramide, oligo esamethylene-l-tartaramide and copolymer between ethylenediamine, adipic and tartaric acids) and allyl α,α′-trehalose/vinyl alcohol (ATR/VOH) copolymer were selected as consolidants. The affinity for wood and the reversibility of the treatments were evaluated together with certain physical properties of treated wood, i.e. maximum water content (MWC), basic density (ρb) and volumetric shrinkage (βv). A specific diagnostic protocol was optimized in order to obtain reproducible and reliable results. A good affinity for a degraded wood rich in lignin was demonstrated for all tested consolidants. For what concerns the reversibility of the treatments, the oligoamides showed higher reversibility than the ATR/VOH copolymer. The penetration ability was good for all selected products. Good results in terms of MWC reduction and ρb increase were obtained with the oligo esamethylene-L-tartaramide, the oligo ethylene-L-tartaramide and the ATR/VOH copolymer.