Crystallisation Properties of Pentaerythritol

Abstract

The results of measurements of density, solubility and refractive index of aqueous solutions of purified pentaerythritol are presented. The density was measured over the range of concentration from zero to saturation over the temperature range 20 - 80°C by the Principle of Archimedes. The refractive index was measured over the same range of conditions with an Abbé refractometer. The preparative methods of pentaerythritol synthesis are briefly reviewed with a view to explaining the possible sources of impurity which occur in the commerical product and which have significant effects on the crystal growth rate. The problem of identifying one of the impurities was tackled. Although this impurity was probably present to an extent of less than 0.1% it had a drastic effect in reducing the rate of crystal growth. A preliminary literature survey of the work done so far on surface energy is presented along with some proposed methods of measurement.