Natural polymers as alternative consolidants for the preservation of waterlogged archaeological wood

Abstract

In recent years there has been increased interest in examining alternative polymers for the conservation of archaeological artefacts, particularly waterlogged timbers, providing better, renewable, greener alternatives to poly(ethylene glycol) (PEG). The degradation of PEG consolidants in the timbers of the 16th century warship Mary Rose has been examined and the rheological and thermal properties of PEG has been compared to its monomethyl and dimethyl ethers and several polysaccharide consolidants (chitosan, guar and 2-hydroxyethyl cellulose) in order to evaluate their potential as alternative consolidants for the conservation of waterlogged wooden artefacts. Additionally, the effect of the polymers on the archaeological wood was characterised by thermogravimetric analysis and solid state NMR. The results suggest that the future of conservation technologies lies with polysaccharide consolidant materials, which show enhanced compatibility with wooden artefacts with no detectable side-effects while also being cheap, with extremely low toxicity, renewable and sustainably resourced.