The Oseberg ship is one of the most important archaeological testimonies of the Vikings. After excavation in 1904, the wooden gravegoods were conserved using alum salts. This resulted in extreme degradation of a number of the objects a hundred years later through acid depolymerisation of cellulose and lignin. The fragile condition of the artefacts requires a reconsolidation which has to be done avoiding water as solvent. We synthesized tert-butyldimethylsilyl (TBDMS) chitosan which is soluble in a 50:50 solution of ethyl acetate and toluene. Measurement of its molecular weight, to anticipate its penetration, provided a challenge as the density difference of the polymer and solvent was too small to provide adequate solute redistribution under a centrifugal field, so a two-stage process was implemented (i) determination of the weight-average molar mass of the aqueous soluble activated precursor, chitosan mesylate, M_w,mc using sedimentation equilibrium with the SEDFIT-MSTAR algorithm, and determination of the degree of polymerisation DP; (ii) measurement of the average degree of substitution DS_TBDMS of the TBDMS group on each chitosan monosaccharide monomer unit using NMR, to augment the M_w,mc value to give the molar mass of the TBDMS-chitosan. For the preparation, we find M_w = 9.8 kg·mol⁻¹, which is within the acceptable limit for penetration and consolidation of degraded wood. Future work will test this on archaeological wood from different sources.

Oseberg船是维京人最重要的考古证据之一。1904年发掘后，使用明矾盐保存了木制的墓穴。一百年后，由于纤维素和木质素的酸解聚，导致许多物品的极端降解。人工制品的脆弱状态需要重新固结，必须避免水作为溶剂。我们合成了叔-丁基二甲基甲硅烷基（TBDMS）壳聚糖，可溶于50:50的乙酸乙酯和甲苯溶液。测量其分子量以预测其渗透性是一个挑战，因为聚合物和溶剂的密度差太小而无法在离心场下提供足够的溶质重新分布，因此实施了两步法（i）确定使用SEDFIT-MSTAR算法的沉降平衡法，测定水溶性活化前体，甲磺酸壳聚糖的重均摩尔质量M _w，mc，并确定聚合度DP；（ii）测量平均取代度DS _TBDMS使用NMR，对每个壳聚糖单糖单体单元上的TBDMS基团的分子量进行测定，以增加M _w，mc值，得到TBDMS-壳聚糖的摩尔质量。对于该制备，我们发现M _w  = 9.8 kg·mol ^-1，这在降解木材的渗透和固结的可接受极限内。未来的工作将在不同来源的考古木材上对此进行测试。