Physical and chemical degradation characteristics of waterlogged archaeological wood from the wenzhou no.1 shipwreck

Abstract The wood of Wenzhou No.1 shipwreck exhibits significant degradation due to the intertidal burial environment. The shipwreck wood mainly consists of Chinese fir ( Cunninghamia lanceolata ) and Chinese cypress ( Cupressus funebris ), with different degradation characteristics. Chinese fir (BD: 0.19–0.33 g/cm³; MWC: 184.8–463.5%), used in load-bearing structures, displayed mild to severe degradation, while cypress (BD: 0.24–0.38 g/cm³; MWC: 171.7–280.6%) applied to joint components exhibited milder degradation. Both species showed substantial holocellulose loss (28–65% of sound wood). FTIR and XRD analyses revealed that both wood species had undergone hemicellulose degradation and cellulose crystallinity reduction, resulting in cell wall delamination and mechanical strength reduction, while residual lignin maintained structural stability, showing a polysaccharide degradation-lignin support pattern. EDS and XRD analyses revealed the presence of inorganic fillers (SiO 2 , CaCO 3 , and FeS 2 ) in wood, with iron content ranging from 0.1–13%. These findings provide valuable scientific references for the conservation of the Wenzhou No.1 shipwreck wood.