Study of behaviour on simulated daylight ageing of artists’ acrylic and poly(vinyl acetate) paint films

Abstract

This work proposes a multi-method approach that combines advanced microscopy (SEM/EDX, AFM) and spectroscopy (UV-vis and FTIR) techniques. This approach not only characterises the behaviour of the additives of two commercial poly(vinyl acetate) (PVAc) and acrylic emulsion paints but also simultaneously characterises the changes in chemical composition and morphology observed in the paint films as a result of ageing due to the paints being exposed to an intense source of simulated daylight. In parallel, a series of mechanical tests were performed that correlate the chemical changes in composition and the changes observed in the films' mechanical properties. This work was a comparative study between both types of acrylic and PVAc paints. The results obtained are of great interest for the modern paint conservation field as they provide valuable information on the mid- and long-term behaviours of these synthetic paints.

Accelerated UV ageing studies of acrylic, alkyd, and polyvinyl acetate paints: Influence of inorganic pigments

“…In case of the PVAc binder the weak broadening of the carbonyl peak in the range between 1,700 and 1,600 cm -1 (Fig. 4c) suggests the increase of free acetic acid [32] after UV ageing according to the Norrish type II mechanism [33], corresponding with the results obtained by the Py-GC/MS analysis with the double-shot. Where the doublet of the most intense symmetric CH 2 bending at 1,465 cm -1 and the less intense asymmetric CH 3 bending at 1,451 cm -1 was shown in the IR spectrum of the unaged alkyd binder, after UV ageing the asymmetric CH 3 bending of the doublet became the most intense one, complemented by an increase in absorption of the symmetric CH 3 bending at 1,385 cm -1 (Figs.…”

Discovering “The Italian Flag” by Fernando Melani (1907–1985)

“…The main molecular markers found in the chromatographic profile were acetic acid, characteristic of a vinyl resin such as Vinavil®, and 2-ethylhexyl-acrylate and 2-ethyl-hexanol, which are distinctive features of an ethylhexyl acrylic resin [39,[42][43]. The other compounds identified were due to the thermal fragmentation pattern of these polymers.…”

Caracterización y propuesta de recuperación de aplacado de mortero polimérico de la parroquia de San Pablo de Sevilla

“…Por lo tanto un polímero de este tipo expuesto a la humedad y lluvia en combinación con la polución, que genera trazas de ácido en el agua, propiciará la hidrólisis de estos enlaces ésteres y la degradación del polímero (22). Adicionalmente, la presencia de grupos cromóforos, como los grupos carbonilo, favorece el desarrollo de reacciones provocadas por la acción de la luz solar (reacciones fotoquímicas) (23). Estas reacciones fotoquímicas propician la formación de radicales libres en el polímero, sobre todo en polímeros acrílicos, que pueden dar lugar a la ruptura de las cadenas.…”