The dissolution and stability of cellulose triacetate in acetone

Abstract

Abstract The solubility behaviour of primary cellulose acetate in acetone has been investigated and it has been found that samples with a degree of substitution (DS) between 2.80 and 2.90 can be completely dissolved by first cooling the polymer‐liquid mixtures to about 190°K then warming to ambient. The efficiency of this process deteriorates rapidly for DS of 2.90–3.0 when only partial solution can be effected. Upper and lower critical solution temperatures have been estimated for these solutions, which provide an indication of the extent of total miscibility for the system. Approximate values for the enthalpy of fusion, together with glass and melting temperatures have been determined by means of a differential scanning calorimeter. The data suggest that acetone can dissolve the smaller crystallites and the associated amorphous regions in the fully acetylated material, but cannot dissolve the larger well ordered regions, unless the sample contains a significant number of hydroxyl groups.