Teaching Polymer Chemistry through Cultural Heritage - Journal of

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Teaching Polymer Chemistry through Cultural Heritage Jocelyn Alcantara-Garcia*,† and Rebecca Ploeger‡ †

Department of Art Conservation, University of Delaware, 303 Old College, 18 E. Main Street, Newark, Delaware 19716, United States ‡ Patricia H. and Richard E. Garman Art Conservation Department, State University of New York (SUNY) Buffalo State, Rockwell Hall 230, 1300 Elmwood Avenue, Buffalo, New York 14222, United States S Supporting Information *

ABSTRACT: Polymers are present in most organic materials in the field of cultural heritage science and art conservation. This makes the study of polymer chemistry necessary in art conservation graduate training programs. Given each program approaches this important topic in different ways, the present paper describes areas of common ground and problems we, as faculty in two of the programs in North America, have found, and how we have addressed them: from stressing the importance of polymer science as part of a holistic educational model to emerging art conservators, to addressing the characterization and degradation of polymers in cultural heritage. While they are seemingly different, both approaches successfully accomplish our overall goal: instill scientific curiosity and problem solving using the extremely ubiquitous class of materials we know as polymers. Consequently, our strategies and the practical exercises we are describing can be easily applied to other areas where polymers are present. KEYWORDS: Polymer Chemistry, Interdisciplinary/Multidisciplinary, Undergraduate Research, Graduate Education/Research, Curriculum, Inquiry-Based/Discovery Learning, Second-Year Undergraduate, Spectroscopy, Upper-Division Undergraduate



INTRODUCTION Art conservation is a multidisciplinary field that requires a deep understanding of art history and material culture, studio art, applied science, patience, and ethics. Admission to a training program in North America is highly competitive, and aspiring conservators must show a strong fundamental understanding of all these arenas, where science includes general and organic chemistry. Conservation students, once admitted, are exposed to more in-depth science, conservation practice, art, and connoisseurship. Given how common polymers are in material cultural heritage, polymer chemistry is now a fundamental topic in conservation. How does one teach polymer chemistry to this unique audience, one that often is more arts or archeology savvy than science-oriented? And, more importantly, how does one teach polymer degradation in a way that is of interest and of use to future professional art conservators? Our students have taken introductory undergraduate chemistry for chemistry majors; however, often they do not encounter polymers in general or organic chemistry, or if they do, it was a minor section within the course. Furthermore, chemistry is very seldom taught with an emphasis in art, although programs like SCIART1 and NSF Chemistry in Art Workshops,2 as well as a handful of schools with undergraduate chemistry courses or course components on conservation science/technical art history, are slowly but surely changing this.3 In a similar way, many museums and cultural institutions are starting to incorporate scientific research into their education and public outreach programs, along with exhibition catalogues as public interest develops.4

after surpassing that point, polymers in cultural objects must be preserved.5 A conservator is often tasked to deal with a polymeric object that may be well beyond its intended service life. They have the challenge of conserving it for posterity, or for as long as possible. This would be through treatment and/or environmental control of display and storage. Albeit seemingly trivial, taking into account that degradation reactions are often autocatalytic, once they begin, with the consequential physical and optical properties changes, treatment options are limited and difficult to execute. For these reasons, synthesis, characterization, and degradation processes are crucial aspects to art conservation training. To make things more difficult, the field of conservation has a strict code of ethics and guidelines for practice when dealing with cultural property.6 The code includes maintaining high standards of conservation practices, respecting the original intent of the artist or object, and selecting conservation materials that will not adversely affect the cultural object in its current state, or in the future. This oftentimes includes minimal intervention through an emerging area known as “preventive conservation” and could encompass “just” moving the artifact to a more suitable, less degrading, tightly controlled atmosphere. It could also use a selection of carefully tested materials approved for conservation treatment purposes (i.e., adhesives, consolidants, varnishes, etc.). Nowadays, most conservation materials have been vetted by cultural heritage (conservation) scientists, to ensure limited to no chemical alteration over long periods of time. This is assuming that the treated object in question is displayed or stored in ideal environmental conditions. The ultimate goal is that the treatment

Teaching Polymer Chemistry to Art Conservation Students

The art conservation field is faced with a unique set of challenges when it comes to ensuring the conservation of cultural heritage around the world. Unlike polymers of day-to-day use, designed to perform for a predetermined service life, and then be replaced © XXXX American Chemical Society and Division of Chemical Education, Inc.

Received: January 8, 2018 Revised: April 5, 2018

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DOI: 10.1021/acs.jchemed.7b00975 J. Chem. Educ. XXXX, XXX, XXX−XXX

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conservation scientists, but rather to train science conversant art conservators who are aware of the materials they are interacting with. The following projects are two effective strategies for preparing conservators for the great challenge of preserving the world’s material and cultural heritage. We trust these strategies can be transferable to other academic disciplines, and that they can offer different approaches to teaching polymer chemistry: through tangible examples of art and material cultural heritage. Although this is not the first time art conservation programs have reached out and suggested using examples of works of art for teaching cross-disciplinary scientific methodologies,3b,c,9 it is the first time, to our knowledge, that we are sharing our polymer chemistry teaching strategies with the science community. We would like to invite our fellow instructors in other areas to consider case studies from cultural heritage artifacts as examples to illustrate such important concepts. The only caution being, to be sensitive, and carefully respect the cultural context of the artifact, and to be informed about the conservation ethics or guidelines established by the American Institute for Conservation of Historic and Artistic Works (AIC).6 We hope this may bring a different perspective to the classroom, which, in turn, will positively affect how we, as a larger population, are taking care of our heritage.

may be safe, and, to the best of the available capabilities, fully reversible at any point in the future.5e,7 For everything stated above, polymer degradation is clearly a key topic for these students. This is related both to the object they are tasked to treat, and to the choice of materials for that purpose. Since the materials they may encounter are impossible to predict, treatment decisions are often on a case-by-case basis, so a solid understanding of polymers is critical. An approach to teaching degradation is to teach polymers from the start, to the middle, to the end. In other words, providing students with insights into polymerization, shaping and additives, and degradation as well as optical and tactile changes that happen during their aging processes. Polymer chemistry can be taught forward (polymerization) and backward (degradation). A critical concept, and justification for all lessons regarding the background and synthesis, is that if one knows something about the process of making polymers, i.e. polymerization, additives, modification for semisynthetics, etc., one may also have an idea of how these polymers may degrade. Polymerization and degradation, in many cases, are linked. Knowing potential issues associated with addition polymerization and polymers, such as monomer structures, impurities, branching, and head-to-head or tail-to-tail additions, or knowing the monomers and linkages of condensation polymers, can be incredibly helpful in predicting degradation pathways. This must be combined with learning the processing aspects of polymers, which is important for understanding the service life and additives, which may influence the long-term stability of an object or a conservation treatment material. The stability of all organic materials depends on the atmosphere (i.e., oxygen, ozone, etc.), pollutants, pests, light, and humidity/temperature fluctuations. In terms of storage and display, many cultural institutions have environmental protocols in place to prevent or mitigate future damage to an object, although it is worth pointing out that degradation may also be mechanical in nature, via improper and/or excessive handling. Or, via inherent vice, which means the material has a naturally short lifespan due to unstable materials used in its production. A prime example of the former is circulating books within a library collection, and of the latter a cellulose nitrate doll that was a child’s toy. This paper explores two strategies to teach and apply challenging concepts in polymer chemistry from different training programs in the United States: the University of Delaware/ Winterthur program, and the State University of New York (SUNY) Buffalo State program.

University of Delaware/Winterthur8b

The WUDPAC program divides science into a first year of fundamental concepts related to the physical and chemical properties of materials of cultural heritage, microscopy, and basics of conservation treatments. The second year focuses on material characterization through spectroscopic and separation techniques. Science classes during the first year directly relate to the material covered in that portion of the year, shaped as “blocks”, 2−4 weeks long; i.e., during paper block, instructors cover cellulose chemistry, its physical−chemical properties, its manufacture, as well as its degradation. This same model is applied to learning about other materials through the course “Properties and Structure of Art Materials”, e.g., textiles (natural and synthetic, proteinaceous, cellulosic), paintings (chemistry of pigments, cross-linking of drying oils), photography (redox reactions of photosensitive materials, developing), etc. Prior to the beginning of their second year, every individual must choose a major and, possibly, a minor in one of the following specialties: objects, furniture, paper, library and archives, textiles, photography, paintings, and, although currently only offered as minor, preventive conservation. It is during their second year that while learning the fundamental principles of numerous spectroscopic and chromatographic techniques (see Supporting Information for syllabi) students apply their knowledge to their area/materials of interest by conducting a technical examination of an object, also known as a “Technical Study” project. Objects can, but do not have to be, treatmentoriented. In addition, students often conduct parallel research that evaluates the behavior of new and original materials (polymers and other degrading molecules). We encourage such studies, especially after receiving a generous award from the Andrew W. Mellon Foundation to support library and archives conservation education (“LACE consortium”).10 Evaluation is performed via “accelerated aging”, which “speeds the natural aging process of (materials) by subjecting (them) to extreme conditions in a climate chamber”.11 A “climate chamber” is a closed system with tight controls of at least one of the three variables: relative humidity, illumination, and temperature. Such chambers can be adjusted



TWO PROGRAMS, TWO TEACHING EXERCISES, ONE GOAL The State University of New York (SUNY) Buffalo State and Winterthur/University of Delaware (WUDPAC) programs in Art Conservation are both three-year long programs, where the first two years are spent in the classroom (summer work projects and internships are common as well), and the final year is an internship spent working in a cultural institution setting under the guidance of a respected professional in the field. Entry into these programs is quite rigorous and highly competitive, and only 10 students are accepted into each of these programs each year.8 The goal of conservation programs like SUNY Buffalo State and WUDPAC is to prepare future conservation professionals in a field where materials are as diverse as human history, and where most materials, including polymers, tend to be beyond their expected service life. The intent of both is not to train B

DOI: 10.1021/acs.jchemed.7b00975 J. Chem. Educ. XXXX, XXX, XXX−XXX

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Figure 1. (A) Chemical structure of nonoxidized cellulose showing the reactive glycosidic linkage and numbering of cyclic glucose units. (B−E) Oxidized cellulose leading to FTIR-evident structural changes: (B) ketones at C2 and C3, (C) aldehydes at C2 and C3, (D) aldehyde at C6, and (E) carboxylic acid at C6.

to “extreme conditions”. For instance, accelerated degradation can occur at 90 °C with cycles of relative humidity between 80% and 35%.12 Accelerated or artificial aging is routinely used in numerous cultural heritage studies.13 It allows prediction of “potential long-term serviceability of material systems under expected conditions of use” and aids in elucidating “the chemical reactions involved and the physical consequences thereof”.14 Although we have access to commercially available equipment, there are other ways in which students could do accelerated aging, i.e., saturated salt solutions in closed containers, exposure to UV lamps on a timer, dry ovens, etc. Studying samples’ degradation under a controlled environment, such as the one accelerated aging provides, has proven extremely useful to reinforce students’ understanding of the materials’ chemistry learned during their first year, therefore complementing their understanding of characterization methods. One concrete example is the study of paper depolymerization: Every conservator has experienced brittleness of old paper, and learning its aging process, illustrated by the following practical example, contributed to grasping the chemistry involved in the process. Paper (cellulose) is one of the most common materials in human history. Its degradation and how it responds to artists’/ writers’ materials and treatments is a suitable excuse to illustrate polymer chemistry, spectroscopy, and chromatography, as demonstrated by accelerated aging tests. Cellulose is a linear polymeric structure formed by units of cyclic glucose bonded by β-1,4-glycosidic linkages, with three hydroxyl groups in carbons 2, 3, and 6 (Figure 1). Its aging leads to chemical changes that are evident using Fourier transform infrared (FTIR) spectroscopy,

which is covered in the second year of the science curriculum.15 Cellulose is characterized by a strong band at 1425 cm−1 (H−C−H and O−H−C in-plane bending) that increases intensity as cellulose ages, and a band at 1316 cm−1 (C−O−H and H−C−C bending), which decreases with aging (Figure 2). It also displays weaker bands at 1335 and 1370 cm−1 (bending C−O−H and H−C−C), which decrease intensities as a result of oxidative reactions.15c Cellulose can degrade by hydrolysis and/or oxidation, among other mechanisms, all occurring either at the glycosidic bond and/or hydroxyl groups.15d,16 When cellulose degrades via oxidation, C3 hydroxyl groups no longer participate in hydrogen bonding, and as a consequence, this type of degradation contributes to the loss of hygroscopic properties, making paper brittle and unresponsive to wet conservation treatments. Further, the presence of acids (frequently associated with inks) can promote acid hydrolysis (also attacking the glycosidic bond) and even dehydration reactions of alcohols, leading to alkenes at C6 and ketones either in C2 or C3.15a The exercise of following paper degradation expands the vision of the technique from a mere identification tool to a tool useful for fundamental research that can inform treatment decisions. Our experiment subjects paper samples with no cultural value to extreme conditions of relative humidity and temperature for 1 and up to 8 weeks to promote or accelerate their degradation.14 During this time, students periodically take samples to monitor paper degradation using FTIR. Figure 2 shows the results of one of our experiments, where the band centered around 1425 cm−1 increases with aging, while the band at approximately 1316 cm−1 decreases. The technique provides some insight into the C

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Figure 2. FTIR spectra collected from Whatman filter paper 1 undergoing accelerated aging (80 °C, 24 h cycles of relative humidity 80−35%, for 0, 4, and 20 days, using an ESPEC BTL-433 climate chamber). Purple, yellow, and green lines correspond to paper at 0, 4, and 20 days of aging, respectively. Solid arrow points to H−C−H and O−H−C in-plane bending band (1425 cm−1), which increases intensity as cellulose ages. Dashed arrow points to C−O−H and H−C−C bending band (1316 cm−1), which decreases with aging.

site for full curriculum details). Much like the WUDPAC program, students can also specialize within a discipline, like archival and library collections (Buffalo State is the principal investigator (PI) in the award from the Andrew W. Mellon Foundation to support library and archives conservation education, or the “LACE consortium”), photographs, furniture, or contemporary materials, although they are encouraged to explore all aspects of their discipline.10 Underpinning everything throughout years one and two is science, along with imaging and documentation. It is the science that is this highlighted here. Students are taught aspects of organic and inorganic chemistry that directly relate to cultural heritage and what they may encounter in their careers. These include scientific concepts and the theory and practical use of analytical instrumentation. In both the class and laboratory, there is a specific focus on critical thinking, problem solving, and interpreting results. The inorganic chemistry component at SUNY Buffalo State includes microscopy and materials, including pigments, metals, glass, and ceramics, and their respective properties, together with their degradation processes. The organic component involves polymers in art and conservation, and preventive conservation, both full term courses each with a laboratory component. Preventive conservation, as stated in the Introduction, is related to the slowing and mitigation of future damage to cultural objects through the careful monitoring and control of environmental conditions. Polymers in art and conservation is taught during the first term of the first year. This starts by looking at polymer nomenclature, basic structures and polymerization, then processing, and, finally, polymer properties as they relate to the field of art conservation (i.e., glass transition, adhesion, viscosity, solubility, etc.). After a thorough introduction to the chemistry of polymers, a series of lectures are dedicated to polymer degradation and accelerated aging. These concepts in chemical stability can also be transferable and related to nonpolymeric organic materials. The lecture schedule/topic order can be found in the Supporting Information.

degradation mechanisms of cellulose. Introducing foreign materials such as pigments and adhesives, and/or performing conservation treatments, will inevitably affect the rate at which paper degrades. This exercise and consequential research allows students to evaluate whether to treat or not, and how, and whether they should be concerned about a certain material if left untreated. Some significant outcomes from processing the gathered scientific evidence are the following: • Why paper becomes less hygroscopic over time. • Why some materials will be harmful while others seem to slow down the degradation rate. • Why some materials are more stable if left untreated. • Why identification of all constituent materials is crucial for treatment. Artificial degradation of conservation and original materials, along with their chemical changes, allows us to track aging processes using other techniques: gel permeation chromatography (GPC) and viscometry reveal depolymerization rate; Raman may show chemical changes if materials are Raman active; colorimetry can quantify color changes; X-ray photoelectron spectroscopy (XPS) can track changes in oxidation state, etc. We are finalizing a project that used this model to study copperbased pigments (unpublished results). This same methodology of accelerated aging may be applied to other materials, such as those used in conservation, including natural and synthetic polymers, which could potentially be used in strategies such as the one the SUNY Buffalo State program successfully uses every year. SUNY Buffalo State, Buffalo, NY8a

While at SUNY Buffalo State, students are taught to approach conservation issues from all angles, and the curriculum is designed in such a way that they explore the three general conservation disciplines, paper, paintings, and objects, before choosing their specialty at the beginning of their second year (please visit SUNY Buffalo State’s Garman Art Conservation program Web D

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Figure 3. Small example of objects available for the “Mystery Polymer Project”. Objects include (general left to right): discolored “Wet Paint” sign, 1960s plastic container, small toy farm spreader, severely degraded photonegatives, small purse with flaking coating, degraded/shattered plastic bag, sticky trading card sleeves, degraded silicon stoppers, discolored broach, damaged painted shell-shaped bowl, distorted and broken LP, damaged telephone hand-set and cord, damaged belt buckle, broken salt shaker top, degraded pink strength elastic, degraded paint tray, degraded decorative tray, sticky green jelly shoe, sticky plastic figurine, and discolored foam.

• Have the mechanical, thermal, chemical or optical properties changed? How? • Suggest reasons why there are conservation concerns (i.e., incorrect storage, general wear and tear, inherent vice, etc.), and how they can be treated? • Are there any potential material incompatibilities? This includes within the object, or between the object and a potential treatment material (i.e., solvent, adhesive, enclosure, etc.)? The two goals that the student must accomplish during the semester are to (1) identify the polymer used to make the object, and as well as possible, the additives present using at least two types of scientific instrumentation; and (2) identify the conservation issues, how they tangibly manifest themselves, and how they can be measured and treated, or recommendations for storage and display. The analytical techniques the students use for this project are Fourier transform infrared spectroscopy (FTIR), pyrolysis−gas chromatography−mass spectrometry (py−GC−MS), and/or Raman spectroscopy (two techniques are needed). Microchemical testing is encouraged as well, and the students should choose a test that will help answer questions they may have about their object, or complement results from an analytical method (i.e., a microchemical test for sulfur, if vulcanized polyisoprene has been identified). Having a physical object to evaluate over the whole term allows the student to gradually build a practical relationship with their object, and to get a deeper understanding of how stable it is over time and under what conditions. With some guidance and supervision, students are responsible for performing their own analyses and data interpretation, giving them early hands-on

A strategy to bring together this large amount of new knowledge is an independent study of a degraded polymer, fondly known as the “Mystery Polymer Project”. This involves an evergrowing collection of common synthetic and natural polymeric objects (Figure 3) showing a variety of typical degradation issues, and it is from this collection that students choose an object for their study; refer to the Supporting Information for a list of objects students have chosen for this project over the past three years. The project is assigned in the first week of the course, before biases for particular materials are formed, and objects are often selected by students out of curiosity, rather than strategy. The average art conservation student responds well to tactile and visual learning, which this project draws heavily on, and as the course moves along, the students are encouraged to think about how the lecture and laboratory topics relate directly to their object. At first glance, this training exercise seems very broad, and it is in terms of materials available for study, but the fundamentals on which the study is built and the goals are the same for each student. A series of questions designed to guide them through the process of interacting with their object, as well as researching the chemical/scientific and conservation literature, are provided with the original handout (please find a Project Description in the Supporting Information); the students are encouraged to build and to elaborate on them for their final papers. These questions include the following: • What is the object, its context in history (i.e., functional object, toy, art, etc.), and when was it made? • What are the conservation concerns, or potential future concerns with it? • What is the polymer, and the additives? E

DOI: 10.1021/acs.jchemed.7b00975 J. Chem. Educ. XXXX, XXX, XXX−XXX

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unique field of study and teaching models, we may motivate educators struggling with teaching critical concepts to think a bit outside the box, and to draw on cultural heritage for inspiration.

experience with the scientific technology, and an appreciation of the skill necessary to run the instrumentation, along with the effort/skills needed for interpreting the data. This independent study approach has been very successful, and has received compliments from the students and faculty in the department. It gives the students an opportunity to choose a material that they are drawn to by curiosity, and brings together the theoretical and the practical aspects of polymers in a way that a single laboratory session cannot always do. It reinforces some of the practical laboratory work (required for other aspects of the course), and prepares them for future conservation treatment decisions as they will repeatedly need to design their own personal scientific questions regarding a treatment in efficient and informative ways, not only during their education, but over their careers. It also emphasizes the importance of communicating their analytical needs and results in an effective way, which is critical in this field, where interaction with scientists is part of the job. As well, it is not uncommon that one of their conservation treatments or projects, while at Buffalo State, goes on to be presented at a national or international conference, or is published in the conservation literature; the culmination of their mystery polymer research is presented as a scientific journal style paper, with relatively strict formatting guidelines, mimicking guidelines required by editors for journal or conference proceedings. This gives them an early perspective into the scientific and conservation literature, not only in how to carefully examine and search the literature, but also in how to efficiently plan and design a research paper, a tool and skill that will evolve during their time at Buffalo State, and over their careers.



ASSOCIATED CONTENT

* Supporting Information S

The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.7b00975. List of objects associated with the “Mystery Polymer” project (PDF, DOCX) Lecture schedule (PDF, DOCX) Syllabus (PDF, DOC) Guidelines for reports (PDF, DOCX)



AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. ORCID

Jocelyn Alcantara-Garcia: 0000-0003-1780-6687 Rebecca Ploeger: 0000-0001-6392-4532 Notes

The authors declare no competing financial interest.



ACKNOWLEDGMENTS We thank the Andrew W. Mellon Foundation for supporting library and archives conservation education, or the “LACE consortium”. In addition, we appreciate the enthusiastic art conservation students at SUNY-Buffalo and WUDPAC programs. We also thank, in particular, E. Heath and M. B. Wiggins (UD) for FTIR spectra.

End Products

Both programs evaluate the one-year project in written and oral formats. All students must turn in a scientifically formatted paper, with strict style protocols, for which we provide relevant comments and suggestions for improvement, like a reviewer would do for an academic journal. In addition, they must give a small presentation to the rest of the class and some faculty (SUNY Buffalo State) and to the public, faculty, and classmates (WUDPAC), followed by a discussion and/or questions. The oral presentation and discussion of the final results serve two purposes: (1) to help the students develop presentation skill, but more importantly, (2) to share their results with their peers. The students can take away not only their results, but also nine other case studies for the future. Please see the Supporting Information for examples and syllabi. Some of the parallel goals are that they learn how to • Proceed through a technical study of a cultural object • Concisely present their findings (written and orally) • Hone their sampling skills • Problem-solve and think independently • Effectively communicate with conservation colleagues, including scientists Regarding the final goal, one of the most important questions to ask follows: Is this analysis necessary, and will the data provide the necessary information to make a sound conservation decision?



REFERENCES

(1) University of Maryland, Baltimore County. Department of Chemistry and Biochemistry: SCIART. https://goo.gl/vcvIo6 (accessed April 3, 2018). (2) (a) National Science Foundation. Division of Chemistry, Chemistry and Materials Research in Cultural Heritage Science (CHS). https://goo.gl/GvLm7K (accessed April 3, 2018). (b) Chemistry in Art Workshop. https://goo.gl/6PMQJX (accessed April 3, 2018). (3) (a) Uffelman, E. S. Technical Examination of 17th-Century Dutch Painting as Interdisciplinary Coursework for Science Majors and Nonmajors. J. Chem. Educ. 2007, 84 (10), 1617−1624. (b) Wells, G.; Haaf, M. Investigating Art Objects through Collaborative Student Research Projects in an Undergraduate Chemistry and Art Course. J. Chem. Educ. 2013, 90 (12), 1616−1621. (c) Nielsen, S. E.; Scaffidi, J. P.; Yezierski, E. J. Detecting Art Forgeries: A Problem-Based Raman Spectroscopy Lab. J. Chem. Educ. 2014, 91 (3), 446−450. (4) (a) Revealing Picasso Conservation ProjectsArt Institute Chicago. http://www.artic.edu/collections/conservation/revealingpicasso-conservation-project (accessed April 3, 2018). (b) LaboratoryThe Indianapolis Museum of Art at Newfields. https:// discovernewfields.org/408/409/conservation-science-laboratory (accessed April 3, 2018). (c) Trentelman, K. Training and Education in Conservation Science. http://www.getty.edu/conservation/ publications_resources/newsletters/20_2/news_in_cons1.html. (d) Conservation ScienceMuseum of Modern Art (MoMA). http:// www.moma.org/explore/multimedia/videos/238/1279 (accessed April 3, 2018). (e) Conservation Science InitiativeThe University of Texas at Dallas. https://www.utdallas.edu/arthistory/conservation/ (accessed April 3, 2018). (f) National Gallery of Art, USAConservation Projects. https://www.nga.gov/conservation/projects.html (accessed April 3, 2018).



CONCLUSIONS Polymer chemistry is an indisputably important part of studying cultural heritage. Conservation science educators know very well that working closely with students is critical to ensuring their deep understanding of materials science. When teaching polymers to larger undergraduate and graduate classes, we know that our almost “one-on-one” approach to teaching may be very difficult to replicate; however, we hope that, by sharing our F

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Journal of Chemical Education

Article

(5) (a) Shashoua, Y. R. Inhibiting the Deterioration of Plasticized Poly(vinyl choride)A Museum Perspective. Danish Polymer Centre, Department of Chemical Engineering, The Technical University of Denmark: Denmark, 2001. (b) Shashoua, Y. R. Plastics. In Conservation ScienceHeritage Materials; May, E., Jones, M., Eds.; RSC Publishing: Cambridge, United Kingdom, 2006; pp 185−211. (c) Smith, M. J.; Kirk, S.; Tate, J.; Cox, D. Material characterization and preservation guidance for a collection of prosthetic limbs developed since 1960. Stud. Conserv. 2014, 59 (4), 256−267. (d) Thomson, M. K. a. R. Conservation of Leather and Related Materials; Butterworth-Heinemann: Burlington, MA, 2006. (e) Wilt, R. L. F. a. M. Evaluation of Cellulose Ethers for Conservation; The Getty Conservation Institute: Marina del Rey, CA, 1990. (f) Kavvouras, P. K.; Kostarelou, C.; Zisi, A.; Petrou, M.; Moraitou, G. Use of Silanol-Terminated Polydimethylsiloxane in the Conservation of Waterlogged Archaeological Wood. Studies in Conservation 2009, 54, 65−76. (6) AICAmerican Institute for Conservation of Artistic and Artistic Works. Code of Ethics and Guidelines for Practice. https://goo.gl/ wqTkvp (accessed April 3, 2018). (7) (a) René de la Rie, E.; McGlinchey, C. W. New Synthetic Resins for Picture Varnishes. Stud. Conserv. 1990, 35 (1), 168−173. (b) Ploeger, R.; McGlinchey, C. W.; de la Rie, E. R. Original and reformulated BEVA® 371: Composition and assessment as a consolidant for painted surfaces. Stud. Conserv. 2015, 60 (4), 217−226. (c) Lomax, S. Q.; Fisher, S. L. An Investigation of the Removability of Naturally Aged Synthetic Picture Varnishes. J. Am. Inst. Conserv. 1990, 29 (2), 181−191. (8) (a) SUNYBuffalo State Program in Art Conservation. http:// artconservation.buffalostate.edu/ (accessed April 3, 2018). (b) Winterthur/University of Delaware Program in Art Conservation (WUDPAC). http://www.artcons.udel.edu/ (accessed April 3, 2018). (9) (a) Smith, G. D.; Nunan, E.; Walker, C.; Kushel, D. Inexpensive, Near-Infrared Imaging of Artwork Using a Night-Vision Webcam for Chemistry-of-Art Courses. J. Chem. Educ. 2009, 86 (12), 1382−1388. (b) Alcantara-Garcia, J.; Szelewski, M. Peak Race: An In-Class Game Introducing Chromatography Concepts and Terms in Art Conservation. J. Chem. Educ. 2016, 93 (1), 154−157. (c) Kafetzopoulos, C.; Spyrellis, N.; Lymperopoulou-Karaliota, A. The Chemistry of Art and the Art of Chemistry. J. Chem. Educ. 2006, 83 (10), 1484−1488. (d) Werner, A. Synthetic Materials in Art Conservation. J. Chem. Educ. 1981, 58 (4), 321−324. (10) SUNY-Buffalo-State-Newsroom. Mellon Foundation Awards $2.1 Million Grant for Art Conservation Project Newswise [Online]; 2017. https://www.newswise.com/articles/mellon-foundation-awards2-1-million-grant-for-art-conservation-project (accessed April 3, 2018). (11) Pork, H. J.; Teygeler, R. Preservation Science Survey. In An Overview of Recent Developments in Research on the Conservation of Selected Analog Library and Archival Materials; Council on Library and Information Resources in Cooperation with European Commission on Preservation and Access: Washington, DC, 2000; p 68. (12) Stol, R.; Pedersoli, J. L.; Poppe, H.; Kok, W. T. Application of size exclusion electrochromatography to the microanalytical determination of the molecular mass distribution of celluloses from objects of cultural and historical value. Anal. Chem. 2002, 74, 2314−1320. (13) (a) Angelini, L. G.; Tozzi, S.; Bracci, S.; Quercioli, F.; Radicati, B.; Picollo, M. Characterization of Traditional Dyes of the Mediterranean Area by Non-Invasive Uv-Vis-Nir Reflectance Spectroscopy. Stud. Conserv. 2010, 55 (sup2), 184−189. (b) Wouters, J.; Grzywacz, C. M.; Claro, A. Markers of Identification of Faded Safflower (Carthamus tinctorius L.) Colorants by HPLC-PDA-MS. Stud. Conserv. 2010, 55, 186−203. (c) Kolar, J.; Malešič, J.; Kočar, D.; Strlič, M.; De Bruin, G.; Koleša, D. Characterisation of paper containing iron gall ink using size exclusion chromatography. Polym. Degrad. Stab. 2012, 97 (11), 2212− 2216. (14) Feller, R. L. Accelerated Aging. Photochemical and Thermal Aspects; The J. Paul Getty Trust: Ann Arbor, MI, 1994. (15) (a) Sistach, M. C.; Ferrer, N.; Romero, M. T. Fourier Transform Infrared Spectroscopy Applied to the Analysis of Ancient Manuscripts. Restaurator 1998, 19, 173−186. (b) Sistach, M. C.; Ferrer, N. Iron Gall Ink Corrosion in Manuscripts. In The Iron Gall Ink Meeting Postprints;

Brown, A. J. E., Ed.; Conservation of Fine Art, University of Northumbria. Newcastle upon Tyne, 2000; pp 73−81. (c) Librando, V.; Minniti, Z. Characterization of Writing Materials of Books of Great Historical-Artistic Value by FT-IR and Micro-Raman Spectroscopy. Conservation Science in Cultural Heritage 2014, 14, 39−50. (d) Workman, J. J. Infrared and Raman Spectroscopy in Paper and Pulp Analysis. Appl. Spectrosc. Rev. 2001, 36 (2−3), 139−168. (16) Ageing and Stabilisation of Paper; Strlič, M., Kolar, J., Eds.; National and University Library: Ljubljana, Slovenia, 2005.

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DOI: 10.1021/acs.jchemed.7b00975 J. Chem. Educ. XXXX, XXX, XXX−XXX