High pressure solid–liquid phase equilibria in synthetic waxes

A high pressure apparatus which rests on a polarizing microscope has been designed to determine visually the liquid–solid phase transitions in complex waxy systems. The apparatus was used to measure the wax disappearance temperature under pressures up to 100 MPa in several synthetic mixtures made up of regular distributions of n-paraffins ranging from n-C13 to n-C24 with various numbers of components.