Assessing the impact and suitability of dense carbon dioxide as a green solvent for the treatment of PMMA of historical value

Bartoletti, A., Soares, I., Ramos, A. M., Shashoua, Y., Quye, A. , Casimiro, T. and Ferreira, J. L. (2023) Assessing the impact and suitability of dense carbon dioxide as a green solvent for the treatment of PMMA of historical value. Polymers, 15(3), 566. (doi: 10.3390/polym15030566)

Abstract

Surface cleaning of plastic materials of historical value can be challenging due to the high risk of inducing detrimental effects and visual alterations. As a result, recent studies have focused on researching new approaches that might reduce the associated hazards and, at the same time, minimize the environmental impact by employing biodegradable and green materials. In this context, the present work investigates the effects and potential suitability of dense carbon dioxide (CO2) as an alternative and green solvent for cleaning plastic materials of historical value. The results of extensive trials with CO2 in different phases (supercritical, liquid, and vapor) and under various conditions (pressure, temperature, exposure, and depressurization time) are reported for new, transparent, thick poly(methyl methacrylate) (PMMA) samples. The impact of CO2 on the weight, the appearance of the samples (dimensions, color, gloss, and surface texture), and modifications to their physicochemical and mechanical properties were monitored via a multi-analytical approach that included optical microscopy, Raman and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopies, and micro-indentation (Vickers hardness). Results showed that CO2 induced undesirable and irreversible changes in PMMA samples (i.e., formation of fractures and stress-induced cracking, drastic decrease in the surface hardness of the samples), independent of the conditions used (i.e., temperature, pressure, CO2 phase, and exposure time).

• Item Type: Articles
• Additional Information: This research was financed by Fundação para a Ciência e a Tecnologia, Ministério da Ciência, Tecnologia, e Ensino Superior (FCT/MCTES), Portugal, through the funded research project “PlasCO2—Green CO2 Technologies for the Cleaning of Plastics in Museums and Heritage Collections” (PTDC/ARTOUT/29692/2017) and the Associate Laboratory for Green Chemistry (LAQV) financed by national funds (UIDB/50006/2020 and UIDP/50006/2020).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Quye, Professor Anita

Creator Roles

Quye, A.: Validation, Writing – review and editing

• Authors: Bartoletti, A., Soares, I., Ramos, A. M., Shashoua, Y., Quye, A., Casimiro, T., and Ferreira, J. L.
• College/School: College of Arts & Humanities > School of Culture and Creative Arts > History of Art
• Journal Name: Polymers
• Publisher: MDPI
• ISSN: 2073-4360
• ISSN (Online): 2073-4360
• Published Online: 21 January 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Polymers 15(3): 566
• Publisher Policy: Reproduced under a Creative Commons License