Thermal analysis of new, artificially aged and archival linen

The thermal degradation of new, and artificially aged fine Ulster linen and archival linen specimens from 19(th) century paintings were compared using thermogravimetric analysis and differential scanning calorimetry. Thermal degradation data from new and artificially aged linen were found to be similar in nature. Archival specimens showed a decreased major degradation temperature, an increase in char remaining at the end of the experiment and some evidence of a depressed glass transition temperature. These indicate natural ageing through chain scission. Evidence of a two-stage degradation process was observed in some archival specimens suggesting that an unknown additive was present.