DYNAMIC-MECHANICAL THERMAL-ANALYSIS FOR THE EVALUATION OF DEACIDIFICATION TREATMENT OF PAINTING CANVASES

The use of non-aqueous deacidification procedures as a preventive cons ervation measure to assist in retarding the deterioration of painting canvases has been suggested by the Conservation Department of the Tate Gallery [1]. The reverse sides of paintings are treated with commerci ally available MMC solution (methoxy magnesium methyl carbonate). The aim of this paper is to describe how dynamic mechanical thermal analys is can be used to evaluate the effects of this treatment. Measurements are described on modern commercially primed canvas samples [2] which show that the MMC treatment does cause an increase in the modulus or s tiffness of the primed canvas materials but that the effect on the T-g is minimal. The response of the treated materials to variations in re lative humidity has also been studied and indications are that the res ponse of treated canvases to variations in relative humidity differs f rom those of the untreated canvases.