INDUSTRIAL ADHESIVES AND FILLERS IN THE CONSERVATION OF POLYMETHYLMETHACRYLATE ARTWORKS: PECULIARITIES, BEHAVIOUR, AGING. A STUDY.
Luciana Tozzi / 
Eleonora Vivarelli / Alessandro Ciccola / Stefano Ridolfi / Isabella Villafranca Soissons
 
KEYWORDS: diagnostic techniques, PMMA adhesives and fillers, PMMA deterioration, aging.
An eligible adhesive for conservation must own appropriate peculiarities, such as chemical and physical compatibility, efficacy, strength, suitable optical properties and, in case of considerable cracks, it must play the role of filler, as well. During the conservation of the Fabio Mauri’s artwork “Grande cinema a luce solida, giallo” at the National Gallery of Modern and Contemporary Art of Rome between 2016 and 2017, the artwork’s characteristics made it necessary to develop a careful and deep study about PMMA-based adhesives.
In facts, the artwork’s peculiarities led to an exclusion of the adhesives normally chosen in conservation, preferring the use of industrial polymethylmetacrylate. Of course, the use of industrial products on artworks involves many risks, above all due to the lack of information given by the producing industries themselves, which must be carefully studied and prevent. A fruitful cooperation between conservators, chemical and physical experts and PMMA producers has been therefore developed in order to obtain evidences of the adhesives’ eligibility.
In this specific case, the artwork showed serious problems concerning the original adhesive (PMMA-based, polymerized in situ during the artwork’s creation), which displayed both a disturbing yellowing and serious cracks: for these reasons, it was no longer suitable to support the anchored element’s weight. It was therefore necessary to identify a new and suitable
adhesive to be set in place of the original one after its removal, in order to guarantee the possibility for the artwork to be exhibited again.
The industrial adhesives taken into consideration have been sampled and studied thanks to the most apt diagnostic technologies applied to Cultural Heritage: mass-spectroscopy, Raman and FT-IR spectrometry, applied before and after heat and UV aging, in order to clarify the adhesives’ characteristics and to predict their future behaviour.
The goal of the research has been to study the peculiarities, behaviour and aging of PMMA- based adhesive in the field of conservation and restoration, and especially in the conservation of contemporary art and design where, in many circumstances, the studied adhesive constitutes the best solution possible.
This research represents, therefore, a first tentative towards an innovation of the current conservation practice.