DEGRADATION CAUSED BY CELLULOSE DIACETATE - ANALYSIS AND PROPOSALS FOR CONSERVATION TREATMENT

For many years cellulose acetate has been considered to be a stable lo ng-term polymer. It has been used widely as a base for cinema film and also as archival material for encapsulating fragile paper. This mater ial has now been proved to be highly unstable, breaking down and relea sing acetic acid and plasticizer. From 1950 to 1975 at the Bibliothequ e Nationale de France, cellulose acetate was used to encapsulate thous ands of documents and fragments in the oriental manuscript collection. Now all these documents have to be removed from this material. This a rticle gives a short description of the production of cellulose acetat e and its properties and then presents the results of analyses perform ed on materials previously used at the Bibliotheque Nationale. Conside ration is then given to the most appropriate measures for saving the d ocuments, most of which are badly damaged. Finally there is a discussi on on the encapsulation of fragile and valuable documents.