Soares, InêsViana, CarolinaBartoletti, AngelicaFrança de Sá, SusanaQuye, AnitaShashoua, YvonneCasimiro, TeresaFerreira, Joana Lia2024-09-232024-09-232024-05-222071-1050PURE: 99835673PURE UUID: d2ce0ce5-be68-4594-b253-85057e5d925eScopus: 85195855457WOS: 001246945600001ORCID: /0000-0003-2445-9361/work/179943550ORCID: /0000-0001-9405-6221/work/207947348http://hdl.handle.net/10362/172281Funding Information: This investigation was supported by national funds through Fundação para a Ciência e a Tecnologia, Ministério da Ciência, Tecnologia e Ensino Superior (FCT/MCTES), Portugal, under the project “PlasCO2: Green CO2 Technologies for the Cleaning of Plastics in Museums and Heritage Collections” (PTDC/ARTOUT/29692/2017), a PhD grant awarded to Inês Soares (SFRH/BD/147015/2019) and the Laboratório Associado para a Química Verde—LAQV (UIDB/50006/2020 DOI 10.54499/UIDB/50006/2020). Publisher Copyright: © 2024 by the authors.Degradation of ester-based polyurethane (PUR) foams results in extensive fragmentation, stickiness, and brittleness both at surfaces and in the bulk. Current methods to conserve museum objects comprising PUR foams include consolidation with solvent-based polymeric solutions. Besides the limitations of spray and brush application for deep consolidant penetration and the impracticality of immersing large-scale objects in solutions, these methods often require large amounts of toxic solvents that are harmful for both the user and environment. Carbon dioxide can be employed as a green solvent as it can be recovered, recycled, and reused without contributing to the greenhouse effect. Supercritical carbon dioxide (scCO2)-assisted consolidation premises are that it may carry the consolidant deeper and deposit it consistently throughout the foam, whilst ensuring minimal interaction with the surface and avoiding material losses in severely degraded objects and the use of toxic solvents. The suitability of scCO2 as a carrier is studied, and the results compared with spray application, a commonly used traditional method. Previous studies have shown that a mixture of alkoxysilanes has great potential for reinforcing the foam’s structure and hydrophobicity when applied by immersion and other impregnation techniques. In this study, scCO2-assisted consolidation has proven to be an effective and green alternative to consolidation by spray, reducing hazardous solvent emissions. After treatment, no visual changes were detected, the samples became less sticky, and the foam flexibility improved significantly. Analytical techniques confirmed the presence of the consolidant in all tested samples, both on the top surface and in-depth layers, in contrast to foams treated by spray.167540907engalkoxysilanesconsolidationpolyurethane foamsupercritical COsustainable conservationComputer Science (miscellaneous)Geography, Planning and DevelopmentRenewable Energy, Sustainability and the EnvironmentEnvironmental Science (miscellaneous)Energy Engineering and Power TechnologyHardware and ArchitectureComputer Networks and CommunicationsManagement, Monitoring, Policy and LawSDG 7 - Affordable and Clean EnergySDG 13 - Climate Actionjournal article10.3390/su16114375https://www.scopus.com/pages/publications/85195855457