Poly(Vinyl Acetate) Paints: A Literature Review of Material Properties, Ageing Characteristics, and Conservation Challenges

Abstract

Since their development in the 1950s, poly(vinyl acetate) [PVAc] paints (also known as vinyl) have been used by many artists, most notably in countries such as Spain, Portugal, and the United Kingdom; they are also used globally as a common binder for house paints. However, only a relatively limited number of heritage scientific studies have focused on vinyl paints. Consequently, many critical aspects of this material, such as the degradation processes, variations in paint formulations, and responses to conservation treatments, remain largely understudied. This article aims to summarise the available relevant information on poly(vinyl acetate) paints from both the scientific and the conservation practice perspectives. The article provides a brief overview of the development of poly(vinyl acetate) paints as artist-grade and household products and the known differences in their formulations. It also focuses on poly(vinyl acetate) ageing behaviour, the physicochemical properties, the recent scientific research on poly(vinyl acetate) material characterisation and degradation, and the main conservation issues regarding these paints, such as those relating to cleaning treatments.

Aging of a Poly(vinyl acetate)-Based White Glue and Its Durability in Contemporary Artworks

“…It is also used as an emulsion in the formulation of adhesives [ 2 ]. Stability issues of PVAC-based materials have been the subject of specific studies since the 1950s, on the degradative behavior under different environments, from thermal to thermo- and photo-oxidative artificial aging conditions [ 3 ]. At temperatures higher than 200 °C, PVAC easily releases acetic acid, leaving C=C double bonds on the main chain [ 4 ], a process that is also favored by UV irradiation [ 5 ].…”

“…Recent studies on oxidation under milder conditions, i.e., at lower temperatures or under simulated solar irradiation, showed good stability of PVAC, with chain scission as the principal degradation mechanism, with very limited deacetylation [ 6 ]. Specific works devoted to PVAC paints show how their complex chemical composition affects the degradation mechanism [ 3 , 7 , 8 , 9 ]. In particular, the presence of vinyl acetate copolymers and external plasticization, as usual in paint formulations, provoke lower stability, which may consist of a slight yellowing and a loss of plasticizer, inducing significant changes in mechanical properties [ 10 ].…”