An innovative methodology for testing and selecting greener solvents for varnishing paintings
Source abstract
Abstract
Organic solvents remain needed for certain treatments in cultural heritage conservation and restoration, including the application of traditional and synthetic resin varnishes on paintings. This research describes a collaborative approach for selecting and testing alternative greener sustainable solvents for this purpose. With commonly used solvent xylene targeted for substitution, initial solvent suggestions were made employing the SUSSOL (sustainable solvent selection and substitution) software tool considering key physical properties of the solvents and specified safety, health and environment hazard boundaries. In parallel HSPiP (Hansen Solubility Parameters in Practice) software was employed after the experimental determination of Hansen solubility parameters and the solubility of selected resins. Fourteen alternative solutions were selected and prepared from commonly used resins for application testing on reference substrates (e.g., Leneta cards and prepared canvas test boards). This testing included (1) the assessment of essential working properties, paint film solvent sensitivity, drying and film formation, and (2) standard coating tests such as water resistance, gloss, and color measurements. Comparable reference resin solutions used as varnishes, prepared with xylene and other solvents, were simultaneously evaluated. First standardized solvent tests provided a practical assessment of the sensitivity of the paint films to the substitute and reference solvents. Varnishing tests were subsequently performed on two historical paintings in order to evaluate the working properties and esthetic qualities of the resin solutions. The novel varnish Regalrez 1094 in isoamyl acetate showed very good working properties and gave a good visual result on both paintings. The resin solution Paraloid B72 in anisole showed good visual results on both paintings, while demonstrating acceptable working properties. This study illustrated that good working properties, protective and visual film qualities could be achieved with varnishes based on typical resins in alternative solvents. Various alternative greener solvents and their mixtures can thereby be suggested for dissolving and applying these resins. The approach within this study acknowledges the individuality of an artwork, which guides the selection of the most appropriate resin solution.
Source: openalex_inverted_index · Quality: baseline
Research context
OpenAlex topics: Chemistry and Chemical Engineering
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (46)
Show source-provided references
1. United Nations 17 Sustainable Development Goals. United Nations Sustainable Development Summit 2015. https://sdgs.un.org/goals (2015).
2. Labadi, S., Giliberto, F., Rosetti, I., Shetabi, L. & Yildirim, E. Heritage and the Sustainable Development Goals: Policy Guidance for Heritage and Development Actors (ICOMOS, 2021).
3. Slimak, L. & Watson, D., translator. The Naked Neanderthal (Allen Lane, 2023).
4. Gombrich, E. H. The Story of Art 15th edn (Phaidon Press, 1989).
5. Elnaggar, A. Nine principles of green heritage science: life cycle assessment as a tool enabling green transformation. Herit. Sci. 12, 1–17 (2024).10.1186/s40494-023-01114-z ↗
6. GoGreen Conservation. Defining Green Conservation. https://gogreenconservation.eu/defining-green-conservation/ (2024).
7. European Confederation of Conservator-Restorers‘ Organisations A.I.S.B.L, Professional Guidelines (II), article. https://www.ecco-eu.org/wp-content/uploads/2021/03/ECCO_professional_guidelines_II.pdf (E.C.C.O, 2024).
8. Sustainability in Conservation. https://www.siconserve.org (2024).
9. Pinheiro, C. et al. Access to sustainability in conservation-restoration practices. Sustainability 16, 1–14 (2024).10.3390/su16177675 ↗
10. Clifford, L. et al. Impacts from sustainability in conservation’s solvent use survey—the results. Presented at Icon Sustainability Group 2024 Conference, 19th-20th November, London (2024).
11. Pascoe, M. Toxic hazards from solvents in conservation. Conservator 4, 25–28 (1980).10.1080/01410096.1980.9994933 ↗
12. Joshi, D. R. & Adhikari, N. An overview on common organic solvents and their toxicity. J. Pharm. Res. Int. 28, 1–18 (2019).10.9734/jpri/2019/v28i330203 ↗
13. Fife, G. R. (ed.) Greener Solvents in Conservation: An Introductory Guide (Archetype Publications in Association with Sustainability in Conservation, 2021).
14. Fife, G. R. & Doutre, M. Experts meeting greener solvents in art conservation. A Report from an Experts’ Meeting Organized by the Getty Conservation Institute and The Royal Institute for Cultural Heritage (KIK-IRPA) (J. Paul Getty Trust, 2024).
15. Byrne, F. P. et al. Tools and techniques for solvent selection: green solvent selection guides. Sustain. Chem. Process. 4, 1–24 (2016).10.1186/s40508-016-0051-z ↗
16. Prat, D. et al. CHEM21 selection guide of classical- and less classical-solvents. Green. Chem. 18, 288–296 (2016).10.1039/C5GC01008J ↗
17. European Parliament and Council regulation concerning the registration, evaluation, authorisation and restriction of chemicals (REACH), establishing a European Chemicals Agency (ECHA). Regulation (EC) No. 1907/2006. https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2007:136:0003:0280:en:PDF
18. Winterton, N. The green solvent: a critical perspective. Clean. Technol. Environ. Policy 23, 2499–2522 (2021).10.1007/s10098-021-02188-8 ↗
19. Gueidão, M., Vieira, E. S., Bordalo, R. & Moreira, P. R. Available green conservation methodologies for the cleaning of cultural heritage: an overview. Estudos de Conservação e Restauro 12, 22–44 (2020).
20. Pieralli, I. et al. A formulation for a new environmentally friendly varnish for paintings. Coatings 13, 1566 (2023).10.3390/coatings13091566 ↗
21. Sutherland, K. The extraction of soluble components from an oil paint film by a varnish solution. Stud. Conserv. 45, 54–62 (2000).10.1179/sic.2000.45.1.54 ↗
22. Phenix, A. & Sutherland, K. The cleaning of paintings: effects of organic solvents on oil paint films. Stud. Conserv. 46, 47–60 (2001).10.1179/sic.2001.46.Supplement-1.47 ↗
23. Phenix, A. Effects of organic solvents on artists’ oil paint films: swelling. in New Insight into the Cleaning of Paintings (eds Mecklenburg, M. F., Charola, A. E. & Koestler, R. J.) 69–76 (Smithsonian Institution Scholarly Press, 2013).
24. Zumbühl, S. Solvents, Solvation, Solubilization and Solution: The Solubility of Materials—An Introduction for Conservators, Including Solubility Data of Selected Conservation Materials. (HDW Publications, 2019).
25. Baij, L. et al. A review of solvent action on oil paint. Herit. Sci. 8, 43 (2020).10.1186/s40494-020-00388-x ↗
26. Liu, C. (Tracy), Alvarez-Martin, A. & Keune, K. Exploring benzyl alcohol derivatives and related compounds in the cleaning of oil paintings. Stud. Conserv. 69, 348–359 (2023).10.1080/00393630.2023.2233374 ↗
27. Macchia, A. et al. Evaluation of green solvents’ applicability for chromatic reintegration of polychrome artworks. Heritage 6, 3353–3364 (2023).10.3390/heritage6030177 ↗
28. Boelsums, M., de Figueiredo Junior, J. C. D. & Cruz Souza, L. A. Low toxicity solvent compositions for varnishes formulations for use in art conservation. Conservar Património 37, 69–79 (2021).
29. Horie, C. Materials for Conservation: Organic Consolidants, Adhesives and Coatings 2nd edn (Butterworth-Heinemann, 2010).
30. Keefe, M. et al. Safer solvent selection for the removal and application of synthetic resins. Conference Presentation American Institute of Conservation Annual Meeting, Salt Lake City, 22nd May (2024).
31. Sels, H., De Smet, H. & Geuens, J. SUSSOL—using artificial intelligence for greener solvent selection and substitution. Molecules 25, 3037 (2020).10.3390/molecules25133037 ↗
32. HSPiP—Hansen solubility parameters. https://www.hansen-solubility.com/HSPiP/ (2023).
33. Kohonen, T. Essentials of the self-organizing map. Neural Netw. 37, 52–65 (2013).10.1016/j.neunet.2012.09.018 ↗
34. Hansen, C. Hansen Solubility Parameters, A User’s Handbook 2nd edn (CRC Press, 2007).10.1201/9781420006834 ↗
35. Husby, L. M., Andersen, C. K., Pedersen, N. B. & Ormsby, B. Evaluating three water-based systems and one organic solvent for the removal of dammar varnish from artificially aged oil paint samples. Herit. Sci. 1, 244 (2023).10.1186/s40494-023-01077-1 ↗
36. Fife, G. R. The solvent star: assessing and documenting solvent selection. Pict. Restor. 56, 41–44 (2020).
37. Proctor, M. & Witten, S. Varnish Workshop (Stichting Restauratie Atelier Limburg, 2023).
38. Samet, W. H. compiler. Varnishes and Surface Coatings: Factors to Consider When Choosing a Varnish (American Institute of Conservation Wiki Online Compendia, 1996).
39. de la Rie, E. R. & Berns, R. S. The relative importance of surface roughness and refractive index in the effects of varnishes on the appearance of paintings. Working Group Scientific Methods of Examination, ICOM Committee for Conservation 13th Triennial Meeting Rio de Janeiro (2002).
40. Dušková-smrčková, M. & Dušek, K. Processes and states during polymer film formation by simultaneous crosslinking and solvent evaporation. J. Mater. Sci. 37, 4733–4741 (2002).10.1023/A:1020843020379 ↗
41. Vinçotte, A. et al. Effect of solvent on PARALOID® B72 and B44 acrylic resins used as adhesives in conservation. Herit. Sci. 7, 42 (2019).10.1186/s40494-019-0283-9 ↗
42. Hansen, E. F. The effects of solvent quality on some properties of thermoplastic amorphous polymers used in conservation. MRS Online Proc. Libr. 352, 807–812 (1995).10.1557/PROC-352-807 ↗
43. de la Rie, E. R. Photochemical and thermal degradation of films of dammar resin. Stud. Conserv. 33, 53–70 (1988).10.1179/sic.1988.33.2.53 ↗
44. Cheng, H. et al. Oxidation characteristics and hazardous of α-pinene, β-pinene and turpentine. Arab. J. Chem. 16, 105322 (2023).10.1016/j.arabjc.2023.105322 ↗
45. Greener Solvents Project Database—In Development. https://siconserve.wpengine.com/greener-solvents/greener-solvents-research-platform/ (2024).
46. National Center for Biotechnology Information. PubChem Compound Summary for CID 31276, Isoamyl Acetate. https://pubchem.ncbi.nlm.nih.gov/compound/Isoamyl-acetate (2024).