The presence of plastics bearing a testimony of the modern and contemporary society has significantly
increased in museum collections over the last decades. The preservation of some polymeric materials, namely
foams, can be a highly demanding challenge for conservators due to inherent characteristics such as
ephemerality and irreversible ageing in short time. The pair of goalkeeper gloves belonging to Robert Enke
(Museu Benfica – Cosme Damião) is an example of a foam-based object showing a severe condition only after
a few decades. Made of a polyisoprene, polybutadiene and polystyrene based foam, the cohesion and
mechanical resistance of the gloves are severely endangered and so far, no efficient and safe treatment
methodologies have been found for these cases. Based on a significance assessment, it was concluded that
the authenticity of the object was intimately related with its materiality and that a consolidation treatment
was of the utmost importance to preserve it. Therefore, in this work, conservation efforts were directed to
the preservation of this highly degraded foam by studying the potential of a novel methodology for its
consolidation based on supercritical carbon dioxide (scCO2).
Despite the successful application of scCO2 in a wide range of conservation treatments for different
materials, its application in the preservation of foams is still an unexplored field. Considering the unique and
versatile features of supercritical fluids (such as a highly tuneable solvent behaviour, low viscosity, high
diffusion rate and lack of interfacial tension), it is expected that scCO2 can be applied as a carrier for
consolidants, allowing an in-depth and homogeneous impregnation with minimal interaction.
This work presents a preliminary study regarding the safety and efficacy of a consolidation with scCO2
as a carrier to treat this composite polymeric foam. Several consolidants were tested in foam samples at
different test conditions. Visual, physical and molecular alterations were followed by pre and post-treatment
characterizations, which included macro and microscopic analyses, dimension and mass variation
measurements, colourimetry and infrared and Raman spectroscopies. Results suggest a successful
impregnation of poly(vinyl acetate) at 40°C and 280 bar. Although further research is still needed to confirm
the safety and efficacy of the method, the promising results show this technology as a potential alternative
for the preservation of plastics within cultural heritage
