MECHANISMS OF DETERIORATION IN CELLULOSE NITRATE BASE ARCHIVAL CINEMATOGRAPH FILM

A number of cellulose nitrate base cinematograph films have been examined by FTIR, u.v./visible spectrometry, viscometry, gel content, moisture regain and pH. Results indicate extensive denitration with cellulosic-backbone scission and ring disintegration. In the metal can, denitration products react with iron to form a very basic iron-nitrogen oxide compound in large quantities, which catalyses further breakdown. The iron itself also acts as a catalyst. Incorporation of a tris stabilizer system comprising metal deactivator, hydroperoxide decomposer and hindered piperidine is seen to increase film longevity by a factor of two. © 1990.