Are All Vinyl Paints The Same? The Impact Of Paint Formulations On Their Stability And The State Of Conservation Of Ângelo De Sousa`s Paintings

• Autor(a) principal: Viana, Carolina dos Reis
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/141569
• topic: Poly(vinyl acetate); Ângelo de Sousa; vinyl emulsions formulations; ageing study; ionic liquids; hydrogels; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

Poly(vinyl acetate) based emulsions were used amongst artists in the 20th century as a binding medium. Vinyl emulsions were cheaper but considered of lesser quality than their better- known counterpart – acrylics, and thus were less used and less studied. As such, there is still a lot to unravel in what concerns their long-term behaviour. The central question addressed in this work, which is inserted within the goals of the research project Plastic Paints in Art: the impact of manufacturing processes on their long-term stability, is the impact of different formulations on the long-term stability of vinyl acetate-based emulsions. Immediate and complete information regarding the use of different additives and their impact is not available for synthetic paints. To complete this information gap, an ageing study with several emulsions based on different plasticizers was conducted. The emulsions in film form suffered accelerated ageing (Xenon-arc light source, =300nm) for 4000hours at and their optical, physical, and chemical changes were followed through a multi-analytical approach. A chronology for the introduction of plasticizers based on historical sources is also presented. PVAc as a homopolymer remained stable after the accelerated ageing, which was something that did not happen for some of the emulsions. It was possible to conclude that different plasticizers, co-monomers, and the quantity in which they are present, influence the emulsions drastically. Ângelo de Sousa, a Portuguese artist who used vinyl paints throughout the 20th century, is presented as a case study. Ângelos private collection was explored, and relationships between the information in the paintings inventory and paintings record were established. Microsamples from selected paintings were analyzed via ATR-FTIR to confirm the nature of the binder. Finally, two paintings with signs of microbial degradation were studied and, within the CleanART- Innovative methodology to clean fungal stains from paper documents and artworks research project, an innovative green technology of hydrogels based on an active principle derived from ionic liquids was tested showing promising results for the removal of fungal stains.