A THEORETICAL INVESTIGATION OF THE PRECONDITIONS FOR OBTAINING THE TRUE THERMODYNAMIC TRANSITION-TEMPERATURE FROM ONLY ONE DSC MEASUREMENT

The true thermodynamic transition temperature can be obtained from one DSC measurement alone. It can be determined by drawing the tangent to the left side of the transition peak in the heat flux versus temperature curve. The intercept of this tangent with the abscissa shows the true thermodynamic transition temperature. This intercept temperature is independent of heat transfer coefficients, heat capacities and the heating rate, provided that (1) the heat capacity of the sample is five or more times higher than that of the sample pan; (2) the heat transfer coefficient between the sample and pan is not smaller than 2 X 10(-2) W cm-2 K-1.