IN-SITU RAMAN SPECTROSCOPIC CHARACTERISATION OF POLYMERS USED IN PAST CONSERVATION TREATMENTS

This paper reports the successful characterisation of polymersfrom past conservation treatments using Raman spectroscopywith a fibre-optic probe. It has been demonstratedfor the first time that this methodology is well suited to thein-situ examination of polymers used as adhesives and gapfillersfor conservation of glass artefacts. By means of aRaman spectroscopic instrument with a fibre-optic probe,conservation polymer spectra were recorded non-destructively,with a spectral resolution of 2 cm-1 in the range 200-3200 cm-1. Polymer identification proved straightforward forgap-fillers and, for adhesives, different polymers were alsosuccessfully distinguished, even in a glass / adhesive /glass bond less than 100 μm in width. In addition to polymeridentification, Fe2O3 was identified as the pigment not onlyin restored areas but also in the original grisaille paint forthe grey toning for the glass pictorial scene.