Degradation of cellulose nitrate adhesive

Abstract

An adhesive based on cellulose nitrate has been used in the British Museum for the repair of antiquities since cellulose nitrate plastic was first made commercially available. The use of cellulose nitrate adhesives in conservation has been criticized and for this reason the stability of the adhesive currently in use has been investigated. The properties of artificially aged samples of the adhesive have been compared with those of artificially aged adhesive-grade cellulose nitrate. The results indicate that the degradation of cellulose nitrate is substantially retarded by the plasticizer in the adhesive. Samples of cellulose nitrate adhesive taken from joins in objects where the date of conservation work is known have been analyzed. The results have been compared with the analysis of the artificially aged samples and a relationship between natural and artificial aging of cellulose nitrate adhesive has been established. The results of this investigation indicate that cellulose nitrate adhesives are stable for at least 30 years, and may be extrapolated to suggest a lifetime of 50 to 100 years under museum conditions in a temperate climate.