Cellulose acetate artefacts in museum collections cover a period from the early 1900's to the present day. Conservators have observed that certain of these objects are showing signs of warping, crazing, cracking, discolouration and shrinkage accompanied by a strong smell of acetic acid. Previous studies on cellulose nitrate artefacts show a correlation existed between the residual sulfate from manufacture and subsequent susceptibility to degradation. A parallel study of the accelerated ageing of modern samples of cellulose acetate and also selected artefacts dating from the 1940's has been carried out. The tests involved exposure of the objects to temperatures of 35 °C, 50 °C and 70 °C and relative humidities of 12 %, 55 % and 75 % for extended periods of time. The samples were monitored for changes both in their visual appearance, mass and chemical composition. Chemical analysis was carried out using micro FT-IR spectrometry and ion chromatography. The changes in the molar mass distribution were studied using gel permeation chromatography. Naturally aged samples have also been studied to help validate the accelerated ageing studies.
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