Moisture Relationships of Photographic Film

Bigourdan, Jean-Louis; Reilly, James M.

doi:10.1179/019713697806124475

Cited by 8 publications

(4 citation statements)

References 5 publications

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“…The standard concentration, C s , which is 1 M, becomes in our representation C s = 1 M/ρ polymer = 0.704 mmol/g, with the density of CDA, ρ polymer = 1.3 g/cm 3 . The initial concentration of acetyl groups in the CDA polymer is expressed as a function of DS: C 0 = DS × 1000/ (anhydroglucose molar mass + DS × acetyl group molar mass), where the anhydroglucose molar mass of the cluster is 29 In that work, they provide two different sets of data, one for the concentration of H 2 O as a function of RH and the latter as a function of the temperature. These sets were fitted to one equation with two independent variables (RH, T).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…These values can be determined experimentally. Different studies in the literature reported experimental data on the concentration of water in cellulose acetate polymers as a function of these parameters. − The provided data were fitted, and the resulting equation was used, as detailed below. However, no such data were reported for the AA concentration in the CA polymer.…”

Section: Resultsmentioning

confidence: 99%

“…The initial concentration of acetyl groups in the CDA polymer is expressed as a function of DS: C 0 = DS × 1000/(anhydroglucose molar mass + DS × acetyl group molar mass), where the anhydroglucose molar mass of the cluster is 171.15 g/mol and the acetyl group molar mass is 59.04 g/mol. The concentration of H 2 O as a function of relative humidity (RH) and temperature of the surrounding environment was fitted from the data presented by Adelstein et al In that work, they provide two different sets of data, one for the concentration of H 2 O as a function of RH and the latter as a function of the temperature. These sets were fitted to one equation with two independent variables (RH, T ).…”

Section: Resultsmentioning

confidence: 99%

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First-Principles Model to Evaluate Quantitatively the Long-Life Behavior of Cellulose Acetate Polymers

et al. 2021

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A deep understanding of the degradation of cellulose diacetate (CDA) polymer is crucial in finding the appropriate long-term stability solution. This work presents an investigation of the reaction mechanism of hydrolysis using electronic density functional theory calculations with the B3LYP/ 6-31++G** level of theory to determine the energetics of the degradation reactions. This information was coupled with the transition-state theory to establish the kinetics of degradation for both the acid-catalyzed and noncatalyzed degradation pathways. In this model, the dependence on water concentration of the polymer as a function of pH and the evaporation of acetic acid from the polymer is explicitly accounted for. For the latter, the dependence of the concentration of acetic acid inside the films with the partial pressure on the surrounding environment was measured by sorption isotherms, where Henry's law constant was measured as a function of temperature. The accuracy of this approach was validated through comparison with experimental results of CDAaccelerated aging experiments. This model provides a step forward for the estimation of CDA degradation dependence on environmental conditions. From a broader perspective, this method can be translated to establish degradation models to predict the aging of other types of polymeric materials from first-principles calculations.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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First-Principles Model to Evaluate Quantitatively the Long-Life Behavior of Cellulose Acetate Polymers

et al. 2021

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“…The selection of materials and preparation steps before storage was based on the experience gathered for freezing archival materials [46][47][48] and the latest recommendations and approaches in the freezer storage of 3D objects [15,49]. Figure 1 reports the different steps needed to prepare the mock-ups for storage.…”

Section: Enclusures For Storage Of Mock-upsmentioning

confidence: 99%

Frozen, Cold, or Cool? Chemical Assessment of the Effectiveness of Storage Conditions for Celluloid 3D Objects

Elsässer,

Angelin,

Montag

et al. 2023

Polymers

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Preserving celluloid artifacts is challenging for museums, as this plastic is highly prone to degradation. Frozen, cold, and cool storage solutions are typically recommended for inhibiting the chemical degradation of celluloid. However, they are rarely implemented for three-dimensional celluloid (3D-CN) objects because low temperatures might cause irreversible effects (e.g., microcracking). This work presents the effects of four different storage temperatures (+23 °C, +13 °C, +9 °C, −15 °C) on the preservation of artificially aged 3D-CN mock-ups, aiming at understanding their effectiveness by measuring molecular weight distribution, camphor, and nitrogen contents after storage. Gel permeation chromatography (GPC) results showed that the least loss of camphor content and fewer polymer chain scissions happened at −15 °C, hinting that this temperature was the best for preservation. However, the heterogeneous nature of celluloid alteration, i.e., the development of degradation gradients in thicker 3D-CN objects (>0.5 mm), made it necessary to apply a novel sampling technique, which selectively considers several depths for analyses from the surface to the core (depth profiling). This depth profiling made monitoring the degradation evolution dependent on the storage conditions in the thicker mock-ups possible. This approach was also used for the first time to quantify the polymer chain scission, camphor loss, and denitration of historical artifacts, indicating a dramatic difference in the degradation stage between surface and core. The effectiveness of frozen storage on the chemical stability of 3D-CN after seven months could support museums to consider reducing the storage temperatures to preserve precious artifacts.

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Use of Design-of-Experiment principles to develop a dose-response function for colour photographs

Fenech

Fearn

Strlič

2012

Polymer Degradation and Stability

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Moisture Relationships of Photographic Film

Cited by 8 publications

References 5 publications

First-Principles Model to Evaluate Quantitatively the Long-Life Behavior of Cellulose Acetate Polymers

First-Principles Model to Evaluate Quantitatively the Long-Life Behavior of Cellulose Acetate Polymers

Frozen, Cold, or Cool? Chemical Assessment of the Effectiveness of Storage Conditions for Celluloid 3D Objects

Use of Design-of-Experiment principles to develop a dose-response function for colour photographs

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