Reversibly cross-linked polymers derived from soybean oil for the consolidation of waterlogged archaeological woods

High-performance conservation materials can greatly enhance the dimensional stability, mechanical properties and environmental stability of waterlogged archaeological woods. However, it is challenging to develop a facile and low cost method to construct mechanically robust bio-based conservation materials with excellent environmental stability that also have satisfactory reversible removability. In this work, bio-based conservation materials are fabricated through the penetration of phenylboronic acids modified epoxidized soybean oil (ESO-PBA) in Zhangwan No.3 shipwreck samples, followed by in-situ reversibly cross-linking ESO chains with boroxines. In-situ formed reversibly cross-linked conservation materials (ESO-B) with high mechanical robustness can prominently improve the dimensional stability, environmental stability and mechanical strength of consolidated woods (W-ESO-B). More importantly, owing to the reversible nature of boroxine cross-linkers, the ESO-B conservation materials in the W-ESO-B sample can be depolymerised into soluble ESO-PBA by ethanol, thereby allowing for the efficient removal of the conservation materials from the archaeological woods without damaging them.