Preliminary Experiments on Model Artificially Altered Samples to Consolidate Degraded and Wet Archaeological Bone with Azelaic Acid

Abstract

As treatments of degraded and wet archaeological bone material is a delicate challenge, no dedicated conservation protocol for this rare material is available today for restorers or museum curators. The current bulking agents have difficulties to diffuse into the close and dense osseous structure. This work aimed at testing the efficiency of an original resin formulation to consolidate in the volume, wet archaeological materials. The tested resin was azelaic acid, a carboxylic diacid comprising nine carbon atoms in its aliphatic chain. Azelaic acid possesses a melting point over more than 100°C and an amazing amphiphile property: azelaic acid is hydrophilic and water soluble at high temperature (70°C) and hydrophobic at room temperature. Consequently, it was proposed to carry out the treatment at 90°C for permitting a good diffusion of acid in the bone porosity, followed by a simple cooling to solidify the resin.