Well-controlled SI-ARGET ATRP of EGDMA for maintaining the dimensions of waterlogged archaeological wood

Controls over the dimensions of waterlogged archaeological wood (WAW) upon drying are a critical issue for its conservation. Surface-initiated activator regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP) has been proven to be an effective consolidation method to increase the dimensional stability. However, the drawback of the current method is that the expansion stress generated during graft polymerization cannot be well controlled. An improved SI-ARGET ATRP system using a bifunctional monomer ethylene glycol dimethacrylate (EGDMA) to introduce a cross-linking process during the polymerization is presented in this paper. Both Pinus massoniana and Sapium sp. samples with different maximum moisture contents as 507% and 863%, respectively, show a reduced volumetric shrinkage of around 5% without any expansion phenomenon after the treatment. This method shows potential applications in the field of WAW conservation and may provide a new solution for consolidation of other organic archaeological objects as well as developing new wood-based materials.