Investigation of cellulose nitrate and cellulose acetate plastics in museum collections using ion chromatography and size exclusion chromatography

One of the goals of the Preservation of Plastics Project at the Getty Conservation Institute is to investigate preventative and conservation strategies for objects made of cellulose ester plastics. To achieve this goal, several analytical protocols were developed and applied to cellulose ester sculptures, design art objects and reference materials. Ion chromatography, size exclusion chromatography, and gas chromatography/mass spectrometry were employed to measure nitric and acetic acids, molecular weight and plasticizer content. The degree of substitution and degree of polymerization for cellulose ester plastics were determined and compared to condition surveys. Cellulose nitrate sculptures by Naum Gabo and Antoine Pevsner, combs from the Harald Szeemann archival collection of the Getty Research Institute, and cellulose acetate sculptures by László Moholy-Nagy and Marcel Duchamp were included in this study.