Effects of acetic acid vapour on the ageing of alkyd paint layers: Multianalytical approach for the evaluation of the degradation processes

Interactions with volatile organic compounds (VOCs) are one of the main issues within the field of the preventive conservation of artworks. VOCs deriving from wooden frames and museum furniture consist in several aldehydes, formic acid and a high abundance of acetic acid. The aim of this study was to evaluate the interactions between alkyd paints and acetic acid that take place during the curing process of the paint layers. A set of reference Winsor & Newton alkyd paint layers was exposed to acetic acid vapour for six months to model these interactions. In order to evaluate the main degradation pathways occurring during the artificial ageing, a multi-analytical approach based on chromatographic and spectroscopic techniques was used. The results describe the main degradation processes of the organic and inorganic components used in the production of the alkyd resin paint.