Strategies for the Storage of Cellulose Acetate Film Continues on Page 3 from the Board President AIC NEWS

Strategies for the Storage of Cellulose Acetate Film Continues on Page 3 from the Board President AIC NEWS

November 2015 Vol. 40, No. 6 Inside From the Board President 2 AIC News 5 Strategies for the Storage Annual Meeting News 6 of Cellulose Acetate Film FAIC News 7 by Douglas Nishimura for PMG Presented at the 2015 PMG Meeting in Cambridge, Massachusetts, JAIC News 9 under the title of “Ten Lost Years” Health & Safety 11 Objects off-gassing deterioration products that are harmful to their own survival isn’t new nor necessarily uncommon. What makes cellu- COLUMN New Materials & Research 15 lose acetate different is not just that it’s sowing its own seeds of destruc- SPONSORED tion, but that it’s also providing fertilizer, sunshine, and water; although BY PM G New Publications 16 cellulose acetate deteriorates on its own, the film base accelerates that destruction. The chemistry of producing an ester from an alcohol and an acid has been known People 16 since the 19th century. The problem lies with the reverse reaction in which the ester is Worth Noting 18 converted back into an alcohol and an acid by hydrolysis. The hydrolysis reaction can be acid catalyzed or alkaline catalyzed, and acid just happens to be the byproduct of the Grants & Fellowships 18 reaction. For cellulose acetate, the ester is not part of the polymer chain, but exists as part of its side groups, so the acid formed by hydrolysis is relatively low in molecular weight, Conservation Training Programs 19 thus mobile and with a moderately high vapor pressure. Measuring acidity levels has long been a Specialty Group Columns 21 method of gauging deterioration for cellulose acetate. The data in Figure 1 suggests that there Network Columns 24 could be specific benefit in removing acetic acid (the catalyst and byproduct); the long flat acidity Courses, Conferences, & Seminars 26 level at the start of deterioration indicates that deterioration in the absence of acetic acid is very slow at controlled room conditions, 70 °F (21 °C) and 50% RH. Recent research has suggested that the situation is more complex, Figure 1 and that attempts to remove acid after the film has reached the autocatalytic point is reached can be harmful; the preservation environment for cellulose acetate is a complex issue that deserves further study and evaluation. Acid migration, humidity and temperature fluctua- tion, and cold temperature storage have all been separately studied to help discern the storage environment that will slow deterioration most efficiently. In 2006, Jean-Louis Bigourdan reported on experiments he conducted on rolls AIC & CAC/ACCR of film that had been artificially deprecated very close to the critical acidity at which in Montreal, Canada autocatalysis overtakes the deterioration rate. The film was divided into four groups, with half placed in commercially available vented cans and the other half in sealed cans. Register now for early-bird pricing for Half of each of these two groups were put into room-condition storage at 21 °C and both the 2016 conference and the 50% to 55% RH, while the other half went into freezer storage at -16 °C and 50% to post-conference tour of Quebec City! 60% RH. After 10.25 years, he found that all of the room-condition stored films were in See pages 6-7 for details. much worse condition, and comparison by acidity measurement showed no significant difference between the vented cans and unvented metals cans. The freezer-stored films all showed little significant change and no difference between the vented plastic cans Strategies for the Storage of Cellulose Acetate Film continues on page 3 From the Board President AIC NEWS AIC News (ISSN 1060-3247) is published Dear Colleagues, bi-monthly by the American Institute for Your board, committees, specialty group officers, and Conservation of Historic & Artistic Works, 1156 task forces have been hard at work! There are lots of 15th Street, NW, Ste. 320, Washington, D.C. 20005; interesting and exciting topics to mention here. 202-452–9545; Fax: 202-452–9328; First, let me touch on just one of the wonderful [email protected] collaborations developing through our work on the www.conservation-us.org upcoming joint meeting with the Canadian Association Send address changes to: for Conservation (Association Canadienne pour la AIC News Conservation et la Restauration), or CAC/ACCR, in 1156 15th Street, NW, Suite 320 Montreal in May. On May 13, 2016, we will host a joint Washington, D.C. 20005 meeting with IAMFA, the International Association of Museum Facilities Administrators. Called Share the Opinions expressed in AIC News are those of the Care: Collaborative Preservation Approaches, this day-long contributors and not official statements of AIC. meeting will bring together conservation professionals, engineers, administrators, and Responsibility for the materials/methods described architects, to discuss topics including the ongoing development of international envi- herein rests solely with the contributors. ronmental guidelines such as ISO 1799 and PAS 198, as well as discussion of collection Deadline for January editorial submissions emergency plans, risk assessment, and conditions in historic house collections. ([email protected]): Building on the excellent work and relationships developed through the Health and December 1, 2015. Safety Committee, AIC is proposing a collaborative partnership with the American We reserve the right to edit for brevity and clarity. Industrial Hygiene Association (AIHA). This will raise awareness and facilitate the dissemination of knowledge about and the effectiveness of health hazard control strate- ADVERTISING gies for conservation professionals, and encourages close working relationships with AIC accepts position-available ads only from occupational and environmental health and safety professionals. equal opportunity employers. All position ads This month, we are looking forward to seeing some of you at the Internal Advisory must conform to the standards for equal oppor- Group (IAG) meeting, which will include discussions about the strategic planning tunity employment. The cost of Internships and process that the boards of AIC and FAIC are currently undergoing. New FAIC board Fellowships, Positions Available, and Classified Ads members, Eden Burgess and Tom Clareson, joined the strategic planning discussions at are: $1.05 per word for members and $2.15 per our last meeting, and contributed new perspective and insight; there is much to discuss word for nonmembers; the minimum charge is $75. at the IAG meeting. Stay tuned for updates on our ongoing discussions of membership The cost of display ads is: categories and requirements for peer-reviewed membership. half page $445; full page $695. I hope you also saw the email blast we sent out asking for your help in responding to Deadlines for advertising copy are: February 10, the call for comments on ivory legislation. A small and very dedicated group, tasked by April 10, June 10, August 10, October 10, and the Education and Training Committee with the development of a position paper on December 10. All ads should be submitted to Ruth ivory, stepped up to assist us in wading through many pages of regulations in order to Seyler at [email protected]. craft both the position paper and a thoughtful response. A number of serious concerns voiced by AIC members have been raised and are being discussed with U.S. Fish and AIC NEWS STAFF Wildlife Service staff members and in consultation with museums nationwide. This Lisa Goldberg, Editor “ivory dream team” comprises Terry Weisser, Nina Owczarek, and Stephanie Hornbeck. Eryl P. Wentworth, Managing Editor I wish to acknowledge their hard work and thank them here. James Martin, Editor, New Materials & Research As we head into the holidays towards the end of this month, I send you my very best Sheila Cummins, Editor, New Publications wishes for peaceful, productive, and happy holidays. Bonnie Naugle, Production Editor With all best wishes, Ruth Seyler, Marketing Director —Pamela Hatchfield, AIC Board President, phatchfield [at] mfa.org Eric Pourchot, Institutional Advancement Director © Copyright 2015. AIC News cannot be reproduced in its entirety without permission from AIC. Individual articles may be reproduced if permission has been granted by the owner of copyright and proper citation attributed. 2 AIC NEWS, November 2015 STRATEGIES FOR THE STORAGE OF CELLULOSE ACETATE FILM Strategies for the Storage of Cellulose Acetate Film preconditioning the film to 21 °C, 20% RH. continued from front cover 4. Acid adsorbents had a minimal impact on reducing the acid content of already degraded cellulose triacetate base film. At best, impractical quantities of acid-adsorbents and the unvented metal cans. More details can be found in the would be required to reduce the acid content of the film 2006 publication of the Journal of Imaging Science and Technology to acceptable levels. In such a situation, cold storage is (Bigourdan, J. Stability of Acetate Film Base: Accelerated-Aging recommended until the film can be duplicated. Data Revisited. JIST 50: 494-501.) 5. The benefits of microenvironments using moisture and Other experiments at the Image Permanence Institute (IPI) acid adsorbents such as molecular sieves and activated silica tested the benefits of adsorbants such as zeolites and silica gel in gel do not equal those obtained by lowering the tempera- sealed cans to see if adsorption of acetic acid from these materials ture of the storage area. helped beyond low humidity conditions (since these materials are 6. The use of microenvironments is recommended when it desiccants). is not possible to prevent high humidity in the storage area. • Silica gel was used at 1.8% and 3.6% by mass of film. This research was part of a NEH-funded project. (Bigourdan, J. • Zeolites were used at both 2.5% and 5% by mass of film. Final Report to the Office of Preservation, National Endowment for the Kodak recommends 37.5 grams of zeolites per thousand Humanities, Grant # PS 20802-94, Environment and Enclosures in feet of 35 mm film or a rate of about 1.8% by mass of film.

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