Thermal Stability in Relation to Hydrolysis of Sodium Decylsulphate in a Solutoin with Nematic Lyotropic Properties

We have studied the effect of temperature as a function of time on sodium decylsulphate in the ternary nematic solution first proposed by Radley and Reeves. The hydrolysis of the ester was followed by recording the pH-profde and by determining the liberated decanol. We found that the ester was subject to slow uncatalyzed hydrolysis in the beginning and to much faster acid catalyzed hydrolysis later on. The decylsulphate underwent in significant cleavage over 48 hours up to at least 70°C with perfect retention of the nematic phase. The results showed that the chemical stability was as good as that of many thermotropic compounds.