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Degraded waste plastics are good models for museum plastics. (a) A latex rubber glove after six months on a beach on the west coast of Denmark. (b) A latex rubber glove after 60 years in the collections of The Royal Danish Arsenal Museum.
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Analysis suggests that progress in conservation of plastics objects and artworks can be described by a series of overlapping mesocycles. Focus has been placed for periods of 5–10 years each on determining the degradation pathways in the 1990s, developing strategies to inhibit those pathways from the late 1990s and, since 2006 on actively stabilizin...
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... fate of waste plastics offers a novel source of information about real time degradation in terrestrial and marine microenvironments (Fig. 3). Environmental scientists are presently determining the sources and concentration of microplastics (1-5 mm in diameter) in the Mediterranean Sea ( Cózar et al., 2015), oceans and in African lakes, and the author is cur- rently contributing experience of the breakdown of plastics to two such projects ( Biginagwa et al., 2016). ...
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... Since the mid-1990s, researchers and conservators in various centers around the world have proposed various methods to slow down degradation processes and improve aesthetics in plastic objects [8]. These suggestions include storage-related strategies [9][10][11], cleaning methods [10,12], consolidation [13], and filling of losses [13]. ...
... These suggestions include storage-related strategies [9][10][11], cleaning methods [10,12], consolidation [13], and filling of losses [13]. However, conservation methods for plastics, including cellulose nitrate, are still in the research, testing, and development stage [8] Applying secondary coatings to cellulose nitrate objects was considered hazardous [14]. In the Auschwitz Museum, we encountered objects on which such coatings had been applied decades ago. ...
The aim of this study was to assess the influence of a protective layer of polyvinyl alcohol on the degradation process of artificial leather based on cellulose nitrate. Samples of the artificial leather were obtained from a suitcase dating back to the first half of the 20th century, not considered a historical artifact. The analysis involved Fourier-transform infrared spectroscopy with attenuated total reflection (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS). Artificial aging was employed for the study. The artificial leather sample with a protective coating of polyvinyl alcohol on a cellulose nitrate base exhibited the lowest degree of degradation due to minimal chemical changes in cellulose esters. The obtained FTIR-ATR spectrum indicated significantly higher nitration of cellulose and, consequently, a lower degree of polymer degradation. The sample without the protective polyvinyl alcohol coating and the sample with the coating removed before artificial aging showed similar reactions.
... For example, the primary degradation reaction for CA is the hydrolysis of its acetyl groups, which produces acetic acid. This acetic acid then catalyzes further hydrolysis and causes additional degradation in both the degrading artifact and any nearby artifacts that are sensitive to acids [2][3][4][5][6][7][8][9]. Surveys of plastic artifacts in British museums in the 1990s showed that the most actively degrading plastics were cellulose nitrate, CA, plasticized poly(vinyl chloride), and polyurethane foam [2,10]. ...
... When artifacts are identified as containing vulnerable plastics such as these, inhibitive conservation [9] may then be practiced, decreasing degradation rates and prolonging the useful lifetimes of those artifacts. In the case of conserving artifacts made of CA, efforts would include mitigating acetic acid [2,3,9]. Thus, to support archival processing and preservation of the PAC, a major goal of this study is to identify artifacts composed of plastics that are vulnerable to degradation. ...
A database was constructed of 134 reference plastic samples and their Raman spectra to aid in the rapid and accurate identification of the polymer composition of mid-twentieth century plastic purses and their component parts from the Plastics Artifacts Collection at Syracuse University Libraries. Work began by making and testing the database, which led to the determination that matching artifact spectra to reference sample spectra worked well for artifact spectra having signal-to-noise ratios down to 30:1. This finding allowed for using reduced laser power as necessary to protect delicate and pigmented artifacts. These studies enabled the definitive chemical identification of seven selected artifacts, showing that the majority are composed of single plastics including polystyrene, poly(methyl methacrylate), or cellulose acetate. However, it was discovered that one of the purses was composed of both poly(methyl methacrylate) and cellulose acetate. The compositions of three artifacts of unknown composition were discovered, corrections to the existing records were made for three other artifacts, and the composition of one artifact was confirmed. This decisive study will contribute to the archival processing and preservation of these artifacts.
... This acetic acid then catalyzes further hydrolysis and causes additional degradation in both the degrading artifact and any nearby artifacts that are sensitive to acids. (2)(3)(4)(5)(6)(7)(8)(9) Surveys of plastic artifacts in British museums in the 1990s showed that the most actively degrading plastics were cellulose nitrate, CA, plasticized polyvinyl chloride, and polyurethane foam. (2,10) When artifacts are identi ed as containing vulnerable plastics such as these, inhibitive conservation may then be practiced, decreasing degradation rates and prolonging the useful lifetimes of those artifacts. ...
... In the case of conserving artifacts made of CA, efforts would include mitigating acetic acid. (2,3,9) Thus, to support archival processing and preservation of the PAC, a major goal of this study is to identify artifacts composed of plastics that are vulnerable to degradation. Artifact records obtained by the SCRC-SUL when it acquired the PAC lack a description of chemical composition for some of the artifacts, while the composition of others is listed but not known de nitively. ...
A database was constructed of 134 reference plastic samples and their Raman spectra to aid in the rapid and accurate identification of the polymer composition of mid-twentieth century plastic purses and their component parts from the Plastics Artifacts Collection at Syracuse University Libraries. Work began by making and testing the database, which led to the determination that matching artifact spectra to reference sample spectra worked well for artifact spectra having signal-to-noise ratios down to 30:1. This finding allowed for using reduced laser power as necessary to protect delicate and pigmented artifacts. These studies enabled the definitive chemical identification of seven selected artifacts, showing that each is composed of polystyrene, polymethyl methacrylate, and/or cellulose acetate. The compositions of three artifacts of unknown composition were discovered, corrections to the existing records were made for three other artifacts, and the composition of one artifact was confirmed. Furthermore, it was discovered that one of the purses was composed of both polymethyl methacrylate and cellulose acetate. This decisive study will contribute to the archival processing and preservation of these artifacts.
... Some issues of conventional techniques for remedial conservation and restoration can be overcome by nano-based formulations specifically developed for the controlled cleaning of surfaces, such as nanofluids composed of micelles or microemulsions applied, for example, to frescos or to graffiti (Giorgi et al. 2017). Nanoscience also provided valuable solutions for polymer film dewetting by water/surfactant/good-solvent mixtures ) and for the consolidation and stabilisation of different artistic surfaces like cellulose (calcium hydroxide nanoparticles in Poggi et al. 2014), painting canvases (combined nanocellulose/nanosilica in Kolman et al. 2018) or bronze (layered double hydroxide nanoparticles filled with corrosion inhibitors in Salzano De Luna et al. 2016), while innovative nano-based solutions are still under development for plastic surfaces (Shashoua 2016). ...
Nanotechnology provides innovative and promising solutions for the conservation of cultural heritage, but the development and application of new nano-enabled products pose concerns regarding their human health and environmental risks. To address these issues, we propose a sustainability framework implementing the Safe by Design concept to support product developers in the early steps of product development, with the aim to provide safer nano-formulations for conservation, while retaining their functionality. In addition, this framework can support the assessment of sustainability of new products and their comparison to their conventional chemical counterparts if any. The goal is to promote the selection and use of safer and more sustainable nano-based products in different conservation contexts. The application of the proposed framework is illustrated through a hypothetical case which provides a realistic example of the methodological steps to be followed, tailored and iterated along the decision-making process.
... It is rigid and requires plasticizers. This polymer is susceptible to acids and concentrated alkalis, which produce a corrosive acetic acid that promotes autocatalysis (Shashoua 2009(Shashoua , 2016. ...
This article presents the intervention process carried out on a work of art created by artist Yolanda Gutiérrez Acosta, using a series of ephemeral materials such as butterfly wings and agave thorns. The work, an installation from 2002, is entitled ‘Efímeras’ (‘Ephemera’) and consists of 12 flowers mounted on acetate sheets and attached to the same with vinyl acetate copolymers and acrylic acid esters (Mowilith®). These flowers are installed on the floor in a bed of dried flowers. The conservation of contemporary art can lead to some previously unimaginable problems for restorers. Current works of art are somewhat material in nature, but they also have a conceptual dimension that is essential for their artistic interpretation. The artist’s participation in the decision-making process prior to the restoration was quite useful. The passage of time, its effect on the work, and the need to understand the possibility of the demise and destruction of the work were implicit as of the onset of its creation, such that, according to the artist, we are forced to reflect upon the possibilities of its future state.
... Access to these publications has significantly aided and enhanced research to connect artifacts and modern production for conservation science, revealing an abundance of information from other chemical industries, such as the related synthetic fibers (Quye, 2014) and synthetic dyes (Quye, 2016). Likewise, it is essential to preserve the physical evidence of the products and documentation of production, and for conservation understanding to grow about materials for informed "interventive conservation" 1 (Shashoua, 2016), and for collection management of artifacts and archives (Brokerhof & Bülow, 2016). Uniting industry and historical material culture in this way offers a potent reconnection between maker and product. ...
The material degradation of an historical artifact through chemical breakdown may place the object at the end of its useful heritage “life” in terms of aesthetic value and appearance. But all is not lost in the ephemeral world of historical synthetic plastics. The chemical analyses of degraded cellulose nitrate artifacts have unlocked material clues that not only help explain stability variations to guide collection care and preservation, but also bring insight into past manufacturing materials, methods and quality control during production. Translating the industrial materials of a degrading artifact by understanding its past to inform its future can revive it with a new cultural significance,
and engages heritage scientists, historians and conservators in an innovative community of “complementary science” as defined by Hasok Chang (2004).
Keywords: conservation science, modern plastic materials, cultural value, analytical chemistry, industrial heritage, history of science, cellulose nitrate, degradation, modern history.
... Access to these publications has significantly aided and enhanced research to connect artifacts and modern production for conservation science, revealing an abundance of information from other chemical industries, such as the related synthetic fibers (Quye, 2014) and synthetic dyes (Quye, 2016). Likewise, it is essential to preserve the physical evidence of the products and documentation of production, and for conservation understanding to grow about materials for informed "interventive conservation" 1 (Shashoua, 2016), and for collection management of artifacts and archives (Brokerhof & Bülow, 2016). Uniting industry and historical material culture in this way offers a potent reconnection between maker and product. ...
The material degradation of an historical artifact through chemical breakdown may place the object at the end of its useful heritage “life” in terms of aesthetic value and appearance. But all is not lost in the ephemeral world of historical synthetic plastics. The chemical analyses of degraded cellulose nitrate artifacts have unlocked material clues that not only help explain stability variations to guide collection care and preservation, but also bring insight into past manufacturing materials, methods and quality control during production. Translating the industrial materials of a degrading artifact by understanding its past to inform its future can revive it with a new cultural significance, and engages heritage scientists, historians and conservators in an innovative community of “complementary science” as defined by Hasok Chang (2004).
Remediation of disfiguring scratches and abrasions on aging plastics challenges even the most experienced conservator. This study assesses the effect of three NOVUS polishing products on remediation of poly (methyl methacrylate) (PMMA). Samples were prepared to mimic the depth and type of scratches observed during conservation treatment performed on vacuum-formed reliefs from the 1960s. The study compares samples of new/unaged PMMA to naturally aged PMMA samples. Two different methods were successfully used to assess the polishing efficacy, which is notoriously challenging to document in transparent and reflective media: (1) image segmentation analysis of photographs to yield scratched area fractions, using three approaches (Li-thresholding, random forest, and convolution neural network); and (2) optical profilometry measurements, which provide surface root-mean-square roughness (RRMS) values. Both methods support the qualitative observations that polishing with the abrasive NOVUS products significantly reduced the surface damage; scratch area fractions decreased from 50–60% to 1–5% across the aged PMMA types after treatment, corresponding to an ∼85% decrease in surface roughness. Critically, the two methods are complementary: the image segmentation results demonstrated a greater visible difference between two degrees of polishing treatments on the new material, while profilometry results were able to parse differences in the degree of scratch reduction between the aged and new materials.
